Author: "Niculescu, G." / Topic: [phys.nexp]physics [physics]/nuclear experiment [nucl-ex] - Searchworks@Jio Institute Digital Library Search Results

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83 results on '"Niculescu, G."'

1. Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

Author: Accardi, A., Achenbach, P., Adhikari, D., Afanasev, A., Akondi, C.S., Akopov, N., Albaladejo, M., Albataineh, H., Albrecht, M., Almeida-Zamora, B., Amaryan, M., Androić, D., Armstrong, W., Armstrong, D.S., Arratia, M., Arrington, J., Asaturyan, A., Austregesilo, A., Avagyan, H., Averett, T., Ayerbe Gayoso, C., Bacchetta, A., Balantekin, A.B., Baltzell, N., Barion, L., Barry, P.C., Bashir, A., Battaglieri, M., Bellini, V., Belov, I., Benhar, O., Benkel, B., Benmokhtar, F., Bentz, W., Bertone, V., Bhatt, H., Bianconi, A., Bibrzycki, L., Bijker, R., Binosi, D., Biswas, D., Boër, M., Boeglin, W., Bogacz, S.A., Boglione, M., Bondí, M., Boos, E.E., Bosted, P., Bozzi, G., Brash, E.J., Briceño, R.A., Brindza, P.D., Briscoe, W.J., Brodsky, S.J., Brooks, W.K., Burkert, V.D., Camsonne, A., Cao, T., Cardman, L.S., Carman, D.S., Carpinelli, M., Cates, G.D., Caylor, J., Celentano, A., Celiberto, F.G., Cerutti, M., Chang, Lei, Chatagnon, P., Chen, C., Chen, J-P, Chetry, T., Christopher, A., Chudakov, E., Cisbani, E., Cloët, I.C., Cobos-Martinez, J.J., Cohen, E.O., Colangelo, P., Cole, P.L., Constantinou, M., Contalbrigo, M., Costantini, G., Cosyn, W., Cotton, C., Dusa, S. Covrig, Cui, Z.-F., D'Angelo, A., Döring, M., Dalton, M.M., Danilkin, I., Davydov, M., Day, D., De Fazio, F., De Napoli, M., De Vita, R., Dean, D.J., Defurne, M., Deur, M., Devkota, B., Dhital, S., Di Nezza, P., Diefenthaler, M., Diehl, S., Dilks, C., Ding, M., Djalali, C., Dobbs, S., Dupré, R., Dutta, D., Edwards, R.G., Egiyan, H., Ehinger, L., Eichmann, G., Elaasar, M., Elouadrhiri, L., El Alaoui, A., El Fassi, L., Emmert, A., Engelhardt, M., Ent, R., Ernst, D.J., Eugenio, P., Evans, G., Fanelli, C., Fegan, S., Fernández-Ramírez, C., Fernandez, L.A., Fernando, I.P., Filippi, A., Fischer, C.S., Fogler, C., Fomin, N., Frankfurt, L., Frederico, T., Freese, A., Fu, Y., Gamberg, L., Gan, L., Gao, F., Garcia-Tecocoatzi, H., Gaskell, D., Gasparian, A., Gates, K., Gavalian, G., Ghoshal, P.K., Giachino, A., Giacosa, F., Giannuzzi, F., Gilfoyle, G.-P., Girod, F-X, Glazier, D.I., Gleason, C., Godfrey, S., Goity, J.L., Golubenko, A.A., Gonzàlez-Solís, S., Gothe, R.W., Gotra, Y., Griffioen, K., Grocholski, O., Grube, B., Guèye, P., Guo, F.-K., Guo, Y., Guo, L., Hague, T.J., Hammoud, N., Hansen, J.-O., Hattawy, M., Hauenstein, F., Hayward, T., Heddle, D., Heinrich, N., Hen, O., Higinbotham, D.W., Higuera-Angulo, I.M., Hiller Blin, A.N., Hobart, A., Holmberg, D.E., Horn, T., Hoyer, P., Huber, G.M., Hurck, P., Hutauruk, P.T.P., Ilieva, Y., Illari, I., Ireland, D.G., Isupov, E.L., Italiano, A., Jaegle, I., Jarvis, N.S., Jenkins, DJ, Jeschonnek, S., Ji, C-R., Jo, H.S., Jones, M., Jones, R.T., Jones, D.C., Joo, K., Junaid, M., Kageya, T., Kalantarians, N., Karki, A., Karyan, G., Katramatou, A.T., Kay, S.J.D., Kazimi, R., Keith, C.D., Keppel, C., Kerbizi, A., Khachatryan, V., Khanal, A., Khandaker, M., Kim, A., Kinney, E.R., Kohl, M., Kotzinian, A., Kriesten, B.T., Kubarovsky, V., Kubis, B., Kuhn, S.E., Kumar, V., Kutz, T., Leali, M., Lebed, R.F., Lenisa, P., Leskovec, L., Li, S., Li, X., Liao, J., Lin, H.-W., Liu, L., Liuti, S., Liyanage, N., Lu, Y., MacGregor, I.J.D., Mack, D.J., Maiani, L., Mamo, K.A., Mandaglio, G., Mariani, C., Markowitz, P., Marukyan, H., Mascagna, V., Mathieu, V., Maxwell, J., Mazouz, M., McCaughan, M., McKeown, R.D., McKinnon, B., Meekins, D., Melnitchouk, W., Meyer, C.A., Meziani, Z.-E., Mezrag, C., Michaels, R., Miller, G.A., Mineeva, T., Miramontes, A.S., Mirazita, M., Mizutani, K., Mkrtchyan, H., Mkrtchyan, A., Moffit, B., Mohanmurthy, P., Mokeev, V.I., Monaghan, P., Montaña, G., Montgomery, R., Moretti, A., Chàvez, J.M. Morgado, Mosel, U., Movsisyan, A., Musico, P., Nadeeshani, S.A., Nakamura, S.X., Nazeer, J., Nefediev, A.V., Neupane, K., Nguyen, D., Niccolai, S., Niculescu, I., Niculescu, G., Nocera, E.R., Nycz, M., Olness, F.I., Ortega, P.G., Osipenko, M., Pace, E., Pandey, B., Pandey, P., Papandreou, Z., Papavassiliou, J., Pappalardo, L.L., Paredes-Torres, G., Paremuzyan, R., Park, S., Parsamyan, B., Paschke, K.D., Pasquini, B., Passemar, E., Pasyuk, E., Patel, T., Paudel, C., Paul, S.J., Peng, J-C., Pentchev, L., Perrino, R., Perry, R.J., Peters, K., Petratos, G.G., Piasetzky, E., Pilloni, A., Pire, B., Pitonyak, D., Pitt, M.L., Polosa, A.D., Pospelov, M., Postuma, A.C., Poudel, J., Preet, L., Prelovsek, S., Price, J.W., Prokudin, A., Puckett, A.J.R., Pybus, J.R., Qin, S.-X., Qiu, J.-W., Radici, M., Rashidi, H., Rathnayake, A.D., Raue, B.A., Reed, T., Reimer, P.E., Reinhold, J., Richard, J.-M., Rinaldi, M., Ringer, F., Ripani, M., Ritman, J., Rittenhouse West, J., Rivero-Acosta, A., Roberts, C.D., Rodas, A., Rodini, S., Rodríguez-Quintero, J., Rogers, T.C., Rojo, J., Rossi, P., Rossi, G.C., Salmè, G., Santiesteban, S.N., Santopinto, E., Sargsian, M., Sato, N., Schadmand, S., Schmidt, A., Schmidt, S.M., Schnell, G., Schumacher, R.A., Schweitzer, P., Scimemi, I., Scott, K.C., Seay, D.A., Segovia, J., Semenov-Tian-Shansky, K., Seryi, A., Sharda, A.S., Shepherd, M.R., Shirokov, E.V., Shrestha, S., Shrestha, U., Signori, A., Slifer, K.J., Smith, W.A., Somov, A., Souder, P., Sparveris, N., Spizzo, F., Spreafico, M., Stepanyan, S., Stevens, J.R., Strakovsky, I.I., Strauch, S., Strikman, M., Su, S., Sumner, B.C.L., Sun, E., Suresh, M., Sutera, C., Swanson, E.S., Szczepaniak, A.P., Sznajder, P., Szumila-Vance, H., Szymanowski, L., Tadepalli, A.-S., Tadevosyan, V., Tamang, B., Tarasov, V.V., Thiel, A., Tong, X.-B., Tyson, R., Ungaro, M., Urciuoli, G.M., Usman, A., Valcarce, A., Vallarino, S., Vaquera-Araujo, C.A., Venturelli, L., Vera, F., Vladimirov, A., Vossen, A., Wagner, J., Wei, X., Weinstein, L.B., Weiss, C., Williams, R., Winney, D., Wojtsekhowski, B., Wood, M.H., Xiao, T., Xu, S.-S., Ye, Z., Yero, C., Yurov, M., Zachariou, N., Zhang, Z., Zhao, Z.W., Zhao, Y., Zheng, X., Zhou, X., Ziegler, V., Zihlmann, B., de Paula, W., de Téramond, G.F., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), National Center for Nuclear Research [Warsaw] (NCBJ), and National Center for Nuclear Research (NCBJ)
Subjects: nucl-th, Nuclear Theory, hep-ex, FOS: Physical sciences, hep-ph, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, High Energy Physics - Experiment, Nuclear Theory (nucl-th), High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Nuclear Physics - Theory, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, Particle Physics - Experiment, Particle Physics - Phenomenology
Abstract: This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena.
Published: 2023

2. Exclusive π− electroproduction off the neutron in deuterium in the resonance region

Author: Tian, Y., Gothe, R. W., Mokeev, V. I., Hollis, G., Amaryan, M. J., Armstrong, W. R., Atac, H., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A., Bossù, F., Boiarinov, S., Bondì, M., Brinkmann, K. T., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Golubenko, A. A., Gosta, G., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hayward, T. B., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. . J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Newton, J., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Počanić, D., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Schumacher, R. A., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: exclusive reaction, data analysis method, effect: off-shell, Settore FIS/04, FOS: Physical sciences, cross section: measured, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], final-state interaction, pi: electroproduction, hadron: final state, kinematics, CLAS, structure function, deuterium: target, n: target, Nuclear Experiment (nucl-ex), Nuclear Experiment, experimental results, Jefferson Lab, photon: virtual
Abstract: New results for the exclusive and quasi-free cross sections off neutrons bound in deuterium ${\gamma}_vn(p) \rightarrow p{\pi}^{-} (p)$ are presented over a wide final state hadron angle range with a kinematic coverage of the invariant mass ($W$) up to 1.825 GeV and the virtual photon four-momentum transfer squared ($Q^{2}$) from 0.4 to 1.0 GeV$^2$. The exclusive structure functions were extracted and their Legendre moments were obtained. Final-state-interaction contributions have been kinematically separated from the extracted quasi-free cross sections off bound neutrons solely based on the analysis of the experimental data. These new results will serve as long-awaited input for phenomenological analyses to extract the $Q^{2}$ evolution of previously unavailable $n \to N^{*}$ electroexcitation amplitudes and to improve state-of-the-art models of neutrino scattering off nuclei by augmenting the already available results from free protons., Comment: The author list has been updated
Published: 2023

3. First observation of correlations between spin and transverse momenta in back-to-back dihadron production at CLAS12

Author: Avakian, H., Hayward, T. B., Kotzinian, A., Armstrong, W. R., Atac, H., Ayerbe Gayoso, C., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Boiarinov, S., Bossù, F., Brinkman, K. T., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D’angelo, A., Dashyan, N., de Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T., Gates, K., Gavalian, G., Ghandilyan, Y., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Heddle, D., Hobart, A., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Kabir, M. L., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Macgregor, I. J. D., Marchand, D., Mascagna, V., Mckinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Munoz Camacho, C., Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., Zurek, M., HEP, INSPIRE, The strong interaction at the frontier of knowledge: fundamental research and applications - STRONG-2020 - 824093 - INCOMING, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CLAS, and European Project: 824093,STRONG-2020
Subjects: angular distribution: asymmetry, hydrogen: liquid, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], electron: polarized beam, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], polarization: longitudinal, FOS: Physical sciences, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], spin: dependence, hadron: transverse momentum, transverse momentum dependence, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), hard scattering, CLAS, deep inelastic scattering, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], structure, Nuclear Experiment (nucl-ex), Nuclear Experiment, hydrogen: target, dihadron: electroproduction, Settore FIS/04, modulation, correlation, spectrometer, hadronization, photon: virtual, Jefferson Lab, experimental results
Abstract: We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction, where two hadrons are produced in opposite hemispheres along the z-axis in the center-of-mass frame, with the first hadron produced in the current-fragmentation region and the second in the target-fragmentation region. The data were taken with longitudinally polarized electron beams of 10.2 and 10.6 GeV incident on an unpolarized liquid-hydrogen target using the CLAS12 spectrometer at Jefferson Lab. Observed non-zero $\sin\Delta\phi$ modulations in $ep \rightarrow e'p\pi^+X$ events, where $\Delta\phi$ is the difference of the azimuthal angles of the proton and pion in the virtual photon and target nucleon center-of-mass frame, indicate that correlations between the spin and transverse momenta of hadrons produced in the target- and current-fragmentation regions may be significant. The measured beam-spin asymmetries provide a first access in dihadron production to a previously unobserved leading-twist spin- and transverse-momentum-dependent fracture function. The fracture functions describe the hadronization of the target remnant after the hard scattering of a virtual photon off a quark in the target particle and provide a new avenue for studying nucleonic structure and hadronization., Comment: 7 pages, 6 figures
Published: 2023

4. First Measurement of $\Lambda$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Author: Chetry, T., El Fassi, L., Brooks, W. K., Dupré, R., El Alaoui, A., Hafidi, K., Patrick Achenbach, Adhikari, K. P., Akbar, Z., Armstrong, W. R., Arratia, M., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. -Th, Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D Angelo, A., Dashyan, N., Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Kabir, M. L., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., Macgregor, I. J. D., Marchand, D., Mascagna, V., Mckinnon, B., Mclauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munoz Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rosner, G., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Weinstein, L. B., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., Zurek, M., Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and CLAS
Subjects: ratio, electron, transverse momentum, GeV, Newport News CEBAF Linac, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], hyperon, meson, target, High Energy Physics - Experiment, iron, fragmentation, deep inelastic scattering, CLAS, propagation, transport theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], multiplicity, structure, enhancement, Nuclear Experiment, deuterium, lead, carbon, nucleus, nucleon, electroproduction, suppression, semi-inclusive reaction, nuclear matter, broadening, beam, production
Abstract: We report results of $\Lambda$ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014~GeV electron beam. These results represent the first measurements of the $\Lambda$ multiplicity ratio and transverse momentum broadening as a function of the energy fraction~($z$) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high~$z$~and~an enhancement at~low~$z$. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high~$z$. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons., Comment: 14 pages, 6 figures
Published: 2022

5. First Observation of Large Missing-Momentum (e,e'p) Cross-Section Scaling and the onset of Correlated-Pair Dominance in Nuclei

Author: Korover, I., Denniston, A. W., Kiral, A., Schmidt, A., Lovato, A., Rocco, N., Nikolakopoulos, A., Weinstein, L. B., Piasetzky, E., Hen, O., Amaryan, M. J., Angelini, Giovanni, Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biondo, L., Biselli, A. S., Bossù, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Caudron, M., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., D Angelo, A., Dashyan, N., Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Duer, M., Dupre, R., Egiyan, H., Mathieu Ehrhart, Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fegan, S., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Golubenko, A. A., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., Macgregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., Mckinnon, B., Migliorati, S., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, Trevor, Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatié, F., Schumacher, R. A., Segarra, E. P., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Wei, Kevin, Wei, X., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: ratio, cross section, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, scaling, nucleus, scattering, nucleon, FOS: Physical sciences, short-range, momentum, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], missing-energy, Nuclear Theory (nucl-th), kinematics, Fermi surface, measured, Nuclear Experiment (nucl-ex), Nuclear Experiment, deuterium
Abstract: We report the first measurement of $x_B$-scaling in $(e,e'p)$ cross-section ratios off nuclei relative to deuterium at large missing-momentum of $350 \leq p_{miss} \leq 600$ MeV/c. The observed scaling extends over a kinematic range of $0.7 \leq x_B \leq 1.8$, which is significantly wider than $1.4 \leq x_B \leq 1.8$ previously observed for inclusive $(e,e')$ cross-section ratios. The $x_B$-integrated cross-section ratios become constant (i.e., scale) beginning at $p_{miss}\approx k_F$, the nuclear Fermi momentum. Comparing with theoretical calculations we find good agreement with Generalized Contact Formalism calculations for high missing-momentum ($> 375$ MeV/c), suggesting the observed scaling results from interacting with nucleons in short-range correlated (SRC) pairs. For low missing-momenta, mean-field calculations show good agreement with the data for $p_{miss}\le k_F$, and suggest that contributions to the measured cross-section ratios from scattering off single, un-correlated, nucleons are non-negligible up to $p_{miss}\approx 350$ MeV/c. Therefore, SRCs become dominant in nuclei at $p_{miss}\approx 350$ MeV/c, well above the nuclear Fermi Surface of $k_F \approx 250$ MeV/c., 7 pages, 4 figures and supplementary materials
Published: 2022

6. Beam-spin asymmetry $\boldsymbol{\Sigma}$ for $\Sigma^-$ hyperon photoproduction off the neutron

Author: Zachariou, N., Munevar, E., Berman, B.L., Bydžovský, P., Cieplý, A., Feldman, G., Ilieva, Y., Nadel-Turonski, P., Skoupil, D., Sarantsev, A.V., Watts, D.P., Amaryan, M.J., Angelini, G., Armstrong, W.R., Atac, H., Avakian, H., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A.S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Bulumulla, D., Burkert, V.D., Carman, D.S., Carvajal, J.C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P.L., Contalbrigo, M., Costantini, G., Crede, V., d'Angelo, A., Dashyan, N., de Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fradi, A., Gavalian, G., Gilfoyle, G.P., Girod, F.X., Gleason, C., Golubenko, A.A., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T.B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ireland, D.G., Isupov, E.L., Jenkins, D., Jo, H.S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Klein, F.J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Livingston, K., Macgregor, I.J.D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., Mckinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munoz Camacho, C., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T.R., Osipenko, M., Ostrovidov, A.I., Pandey, P., Paolone, M., Pappalardo, L.L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J.W., Prok, Y., Raue, B.A., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R.A., Sharabian, Y.G., Shirokov, E.V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I.I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Wei, K., Wei, X., Wishart, R., Wood, M.H., Yale, B., Zhang, J., Zhao, Z.W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: accelerator, partial wave, nucleon, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], photon: energy, resonance: coupling, High Energy Physics - Experiment, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], branching ratio, hyperon: photoproduction, Nuclear Experiment, photon: beam, isobar model, asymmetry, Jefferson Lab, experimental results
Abstract: We report a new measurement of the beam-spin asymmetry $\boldsymbol{\Sigma}$ for the $\vec{\gamma} n \rightarrow K^+\Sigma^-$ reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions from an isobar model indicate strong sensitivity to $N(1720)3/2^+$, $\Delta(1900)1/2^-$, and $N(1895)1/2^-$, with the latter being a state not considered in previous photoproduction analyses. When our data are incorporated in the fits of partial-wave analyses, one observes significant changes in $\gamma$-$n$ couplings of the resonances which have small branching ratios to the $\pi N$ channel., Comment: 9 pages, 4 figures, Hadron Spectroscopy
Published: 2022

7. Improved $\Lambda p$ Elastic Scattering Cross Sections Between 0.9 and 2.0 GeV/c and Connections to the Neutron Star Equation of State

Author: CLAS Collaboration, Rowley, J., Compton, N., Djalali, C., Hicks, K., Price, J., Zachariou, N., Adhikari, K. P., Armstrong, W. R., Atac, H., Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Gavalian, G., Girod, F. X., Glazier, D. I., Golubenko, A., Gothe, R. W., Griffioen, K., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Korover, I., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Pogorelko, O., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wishart, R., Wood, M. H., Yale, B., Yurov, M., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: 25.55.Cj E, data analysis method, Nuclear Theory, Newport News CEBAF Linac, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, kinematics, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 13.75.Ev, ddc:530, cross section: elastic scattering, neutron star, p Lambda: elastic scattering, 13.85.Lg, Nuclear Experiment, nucleus: equation of state, Lambda: momentum, channel cross section: measured, Jefferson Lab, experimental results
Abstract: Physical review letters 127(27), 272303 (2021). doi:10.1103/PhysRevLett.127.272303, Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state. Yet, compared to other elastic scattering processes, there is very little data on ��N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the ��p��p elastic scattering cross section in the incident �� momentum range 0.9��2.0 GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments., Published by APS, College Park, Md.
Published: 2021

8. Photoproduction of the $f_2(1270)$ meson using the CLAS detector

Author: Carver, M., Celentano, A., Hicks, K., Marsicano, L., Mathieu, V., Pilloni, A., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. E., Fassi, L. E., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Gavalian, G., Gevorgyan, N., Gilfoyle, G. P., Girod, F. X., Gothe, R. W., Griffioen, K. A., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Holtrop, M., Huang, Q., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., H. S., Jo, Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., Macgregor, I. J. D., Marchand, D., Mascagna, V., Mccracken, M. E., Mckinnon, B., Meziani, Z. E., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. M., Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Yale, B., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: Quark Structure, Standard Model, Glueball, mesons, pions, High Energy Physics::Lattice, Nuclear Theory, FOS: Physical sciences, Socio-culturale, f2(1270): photoproduction, quark antiquark, quantum number, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, beam: energy, +pi%2B+pi%22">rho(770) --> pi+ pi, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Economica, PE2_2, background: low, PE2_1, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ddc:530, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, PE2_3, M005M, +pi0+pi0+p%22">photon rho(770) --> pi0 pi0 p, hep-ex, Physics, Settore FIS/04, High Energy Physics::Phenomenology, M005W, Ambientale, suppression, differential cross section, Elementary Particles and Fields, High Energy Physics::Experiment, Particle Physics - Experiment, Jefferson Lab
Abstract: The quark structure of the $f_2(1270)$ meson has, for many years, been assumed to be a pure quark-antiquark ($q\bar{q}$) resonance with quantum numbers $J^{PC} = 2^{++}$. Recently, it was proposed that the $f_2(1270)$ is a molecular state made from the attractive interaction of two $\rho$-mesons. Such a state would be expected to decay strongly to final states with charged pions, due to the dominant decay $\rho \to \pi^+ \pi^-$, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction $\gamma p \to \pi^0 \pi^0 p$, using the CLAS detector at Jefferson Lab for incident beam energies between 3.6-5.4~GeV. Differential cross sections, $d\sigma / dt$, for $f_2(1270)$ photoproduction are extracted with good precision, due to low backgrounds, and are compared with theoretical calculations., Comment: 5 pages, 4 figures
Published: 2021

9. Observation of Beam Spin Asymmetries in the Process $ep\rightarrow{e}^{'}{\pi}^{+}{\pi}^{-}X$ with CLAS12

Author: Hayward, T.B., Dilks, C., Vossen, A., Avakian, H., Adhikari, S., Angelini, G., Arratia, M., Atac, H., Ayerbe Gayoso, C., Baltzell, N.A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A.S., Bondì, M., Bossù, F., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Bulumulla, D., Burkert, V.D., Carman, D.S., Carvajal, J.C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B.A., Cole, P.L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T.A., Gavalian, G., Gilfoyle, G.P., Girod, F.X., Glazier, D.I., Golubenko, A.A., Gothe, R.W., Gotra, Y., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hicks, K., Hobart, A., Holtrop, M., Ireland, D.G., Isupov, E.L., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S.E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., Macgregor, I.J.D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., Mckinnon, B., Meziani, Z.E., Mirazita, M., Mokeev, V., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Naidoo, P., Nanda, S., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T.R., Osipenko, M., Paolone, M., Pappalardo, L.L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Raue, B.A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Segarra, E.P., Sharabian, Y.G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I.I., Strauch, S., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D.P., Wei, K., Wei, X., Wood, M.H., Yale, B., Zachariou, N., Zhang, J., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: deep inelastic scattering: semi-inclusive reaction, Nuclear Theory, collinear, parton: distribution function, gluon, GeV, Newport News CEBAF Linac, helicity: asymmetry: measured, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], fragmentation function, quark, p: target, CLAS, two-pion, Physics::Accelerator Physics, High Energy Physics::Experiment, spectrometer, electron: beam, Nuclear Experiment, spin: asymmetry, Jefferson Lab, Nuclear Physics
Abstract: International audience; The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G1⊥. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark.
Published: 2021

10. Ruling out Color Transparency in Quasielastic $^{12}$C(e,e'p) up to $Q^2$ of 14.2 (GeV/c)$^2$

Author: Bhetuwal, D., Matter, J., Szumila-Vance, H., Kabir, M. L., Dutta, D., Ent, R., Abrams, D., Ahmed, Z., Aljawrneh, B., Alsalmi, S., Ambrose, R., Androic, D., Armstrong, W., Asaturyan, A., Assumin-Gyimah, K., Gayoso, C. Ayerbe, Bandari, A., Basnet, S., Berdnikov, V., Bhatt, H., Biswas, D., Boeglin, W. U., Bosted, P., Brash, E., Bukhari, M. H. S., Chen, H., Chen, J. P., Chen, M., Christy, E. M., Covrig, S., Craycraft, K., Danagoulian, S., Day, D., Diefenthaler, M., Dlamini, M., Dunne, J., Duran, B., Evans, R., Fenker, H., Fomin, N., Fuchey, E., Gaskell, D., Gautam, T. N., Gonzalez, F. A., Hansen, J. O., Hauenstein, F., Hernandez, A. V., Horn, T., Huber, G. M., Jones, M. K., Joosten, S., Karki, A., Keppel, C., Khanal, A., King, P. M., Kinney, E., Ko, H. S., Kohl, M., Lashley-Colthirst, N., Li, S., Li, W. B., Liyanage, A. H., Mack, D., Malace, S., Markowitz, P., Meekins, D., Michaels, R., Mkrtchyan, A., Mkrtchyan, H., Nazeer, S. J., Nanda, S., Niculescu, G., Niculescu, I., Nguyen, D., Nuruzzaman, Pandey, B., Park, S., Pooser, E., Puckett, A., Rehfuss, M., Reinhold, J., Santiesteban, N., Sawatzky, B., Smith, G. R., Sun, A., Tadevosyan, V., Trotta, R., Wood, S. A., Yero, C., Zhang, J., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Hall C
Subjects: Nuclear Theory, carbon: target, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, color: transparency, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Nuclear Theory (nucl-th), High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], p: recoil, Nuclear Experiment (nucl-ex), Nuclear Experiment, yield: measured, Nuclear Physics, nucleus: target, electron nucleus: scattering, momentum transfer, p: momentum, inelastic scattering, impulse approximation: plane wave, quantum chromodynamics: effect, nucleus: transparency, experimental results, Jefferson Lab
Abstract: Quasielastic $^{12}$C$(e,e'p)$ scattering was measured at space-like 4-momentum transfer squared $Q^2$~=~8, 9.4, 11.4, and 14.2 (GeV/c)$^2$, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no $Q^2$ dependence, up to proton momenta of 8.5~GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured $Q^2$ scales in exclusive $(e,e'p)$ reactions. These results impose strict constraints on models of color transparency for protons., 5 pages, 2 figures
Published: 2021

11. Observation of Beam Spin Asymmetries in the Process $e p \rightarrow e \pi^{+}\pi^{-}X$ with CLAS12

Author: Hayward, T. B., Dilks, C., Vossen, A., Avakian, H., Adhikari, S., Angelini, G., Arratia, M., Atac, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondì, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T. A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hicks, K., Hobart, A., Holtrop, M., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Nanda, S., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., HEP, INSPIRE, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: electron p: deep inelastic scattering, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], electron: polarized beam, Nuclear Theory, polarization: longitudinal, parton: distribution function, collinear, helicity: asymmetry: measured, GeV, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Newport News CEBAF Linac, fragmentation function, High Energy Physics - Experiment, quark, p: target, two-pion, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], electron: beam, Nuclear Experiment, Nuclear Physics, deep inelastic scattering: semi-inclusive reaction, gluon, Physics::Accelerator Physics, High Energy Physics::Experiment, spectrometer, pi: pair production, spin: asymmetry, Jefferson Lab, experimental results
Abstract: The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function $e(x)$, which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function $G_1^\perp$. A clear sign change is observed around the $\rho$ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark., Comment: 6 pages, 5 figures
Published: 2021

12. First measurement of direct photoproduction of the a2(1320)0 meson on the proton

Author: Celentano, A., Battaglieri, M., De Vita, R., Marsicano, L., Mathieu, V., Pilloni, A., Szczepaniak, A., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Barion, L., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., Cruz-Torres, R., D'Angelo, A., Dashyan, N., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Gevorgyan, N., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., Lucherini, V., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., McCracken, M. E., McKinnon, B., Meziani, Z.-E., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R. A., Shrestha, U., Sokan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Hadronic Physics and QCD, Socio-culturale, FOS: Physical sciences, Regge, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], beam: energy, High Energy Physics - Experiment, Nuclear Theory (nucl-th), differential cross section: measured, High Energy Physics - Experiment (hep-ex), PE2_2, PE2_1, CLAS, mass spectrum: (pi0 eta), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], angular distribution, photon p: exclusive reaction, Nuclear Experiment (nucl-ex), Nuclear Experiment, PE2_3, Nucleons, Mesons, Settore FIS/04, photon p: inelastic scattering, partial wave analysis, photon: energy, Photoproduction, meson: photoproduction, experimental results
Abstract: We present the first measurement of the exclusive reaction $\gamma p \rightarrow a_2(1320)^0 \, p$ in the photon energy range $3.5$-$5.5$ GeV and four-momentum transfer squared $0.2, Comment: Version accepted for publication in PRC, "Rapid Communications" section
Published: 2020

13. Probing the core of the strong nuclear interaction

Author: Schmidt, A, Pybus, J, Weiss, R, Segarra, E, Hrnjic, A, Denniston, A, Hen, O, Piasetzky, E, Weinstein, L, Barnea, N, Strikman, M, Larionov, A, Higinbotham, D, Adhikari, S, Amaryan, M, Angelini, G, Asryan, G, Atac, H, Avakian, H, Gayoso, C, Baashen, L, Barion, L, Bashkanov, M, Battaglieri, M, Beck, A, Bedlinskiy, I, Benmokhtar, F, Bianconi, A, Biselli, A, Bossu, F, Boiarinov, S, Brahim, M, Briscoe, W, Brooks, W, Burkert, V, Cao, F, Carman, D, Carvajal, J, Celentano, A, Chatagnon, P, Chetry, T, Ciullo, G, Clark, L, Cohen, E, Cole, P, Contalbrigo, M, Crede, V, Cruz-Torres, R, D'Angelo, A, Dashyan, N, De Vita, R, De Sanctis, E, Defurne, M, Deur, A, Diehl, S, Djalali, C, Duer, M, Dugger, M, Dupre, R, Egiyan, H, Ehrhart, M, El Alaoui, A, El Fassi, L, Eugenio, P, Filippi, A, Forest, T, Gavalian, G, Gilad, S, Gilfoyle, G, Giovanetti, K, Girod, F, Giuseppe, C, Glazier, D, Golovatch, E, Gothe, R, Griffioen, K, Guo, L, Hafidi, K, Hakobyan, H, Hanretty, C, Harrison, N, Hattawy, M, Hauenstein, F, Hayward, T, Hicks, K, Holtrop, M, Ilieva, Y, Illari, I, Ireland, D, Ishkanov, B, Isupov, E, Jenkins, D, Hs, J, Joo, K, Keller, D, Khachatryan, M, Khanal, A, Khandaker, M, Kim, C, Kim, W, Klein, F, Korover, I, Kubarovsky, V, Lanza, L, Leali, M, Lenisa, P, Macgregor, I, Marchand, D, Markov, N, Marsicano, L, Mascagna, V, Beck, S, Mckinnon, B, Mirazita, M, Mokeev, V, Camacho, C, Mustafa, B, Nadel-Turonski, P, Nanda, S, Niccolai, S, Niculescu, G, Osipenko, M, Ostrovidov, A, Paolone, M, Pappalardo, L, Paremuzyan, R, Park, K, Pasyuk, E, Patsyuk, M, Phelps, W, Pogorelko, O, Price, J, Prok, Y, Protopopescu, D, Ripani, M, Riser, D, Rizzo, A, Rosner, G, Rossi, P, Sabatie, F, Salgado, C, Schmookler, B, Schumacher, R, Sharabian, Y, Shrestha, U, Skorodumina, I, Sokhan, D, Soto, O, Sparveris, N, Stepanyan, S, Strakovsky, I, Strauch, S, Tan, J, Tyler, N, Ungaro, M, Venturelli, L, Voskanyan, H, Voutier, E, Wang, R, Watts, D, Wei, X, Wood, M, Zachariou, N, Zhang, J, Zhao, Z, Zheng, X, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Nuclear Theory, nucleon: pair, Socio-culturale, Nuclear Interactions, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, spin: dependence, 01 natural sciences, 7. Clean energy, Nuclear physics, Nuclear Theory (nucl-th), PE2_1, CLAS, 0103 physical sciences, quantum chromodynamics, Neutron, density: high, Nuclear Models, Quarks and Gluons, Electron Scattering, Spin Dependent Cross Sections, Nuclear Experiment (nucl-ex), 010306 general physics, neutron star, Nuclear Experiment, PE2_3, nucleus: interaction, Physics, Quantum chromodynamics, Multidisciplinary, 010308 nuclear & particles physics, Settore FIS/04, Nuclear matter, Fundamental interaction, quark gluon: interaction, Neutron star, electron: scattering, kinematics, nuclear matter, Atomic nucleus, Quark–gluon plasma, Nucleon, experimental results
Abstract: The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of Quantum Chromodynamics (QCD). However, as these equations cannot be solved directly, physicists resort to describing nuclear interactions using effective models that are well constrained at typical inter-nucleon distances in nuclei but not at shorter distances. This limits our ability to describe high-density nuclear matter such as in the cores of neutron stars. Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations thereby accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta above 400 MeV/c. As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor-force to a predominantly spin-independent scalar-force. These results demonstrate the power of using such measurements to study the nuclear interaction at short-distances and also support the use of point-like nucleons with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of atomic nuclei., Comment: Total 26 pages, 13 figures. Main text: 8 pages, 3 figures. Methods section: 6 pages. Extended Data: 8 figures, 1 table. Supplementary Materials: 8 pages, 2 figures
Published: 2020
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14. Exclusive ${\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4 GeV${^{2}}$ ${\leq~ Q^{2} \leq~1}$ GeV${^{2}}$

Author: Markov, N., Joo, K., Burkert, V. D., Mokeev, V. I., Smith, L. C., Ungaro, M., Adhikari, S., ~Amaryan, M. J., Angelini, G., ~Atac, H., ~Avakian, H., Gayoso, C. Ayerbe, ~Baltzell, N. A., Barion, L., ~Battaglieri, M., ~Bedlinskiy, I., Benmokhtar, F., ~Biselli, A. S., ~Bossù, F., ~Boiarinov, S., ~Briscoe, W. J., ~Brooks, W. K., ~Carman, D. S., ~Carvajal, J. C., ~Celentano, A., ~Chatagnon, P., Chetry, T., ~Cole, P. L., ~Contalbrigo, M., ~Crede, V., Ciullo, G., ~D'Angelo, A., ~Dashyan, N., ~De~Vita, R., ~De~Sanctis, E., Defurne, M., ~Deur, A., Diehl, S., ~Djalali, C., ~Dupre, R., ~Ehrhart, M., ~El~Alaoui, A., ~El~Fassi, L., ~Eugenio, P., ~Evans, C., ~Filippi, A., ~Ghandilyan, Y., ~Girod, F. X., ~Golovatch, E., ~Gothe, R. W., ~Griffioen, K. A., ~Guidal, M., ~Hafidi, K., ~Hakobyan, H., ~Hattawy, M., ~Hayward, T. B., ~Hicks, K., ~Holtrop, M., ~Ilieva, Y., ~Ireland, D. G., ~Ishkhanov, B. S., ~Isupov, E. L., ~Jenkins, D., ~Jo, H. S., ~Keller, D., ~Khachatryan, M., ~Khanal, A., ~Khandaker, M., ~Kim, A., ~Kim, C. W., ~Kim, W., ~Klein, F. J., ~Kubarovsky, V., Lanza, L., ~Leali, M., ~Livingston, K., ~MacGregor, I . J . D., ~Marchand, D., ~Mascagna, V., ~McKinnon, B., ~Mineeva, T., ~Mirazita, M., ~Nadel-Turonski, P., ~Nanda, S., ~Niccolai, S., ~Niculescu, G., ~Osipenko, M., ~Paolone, M., ~Pappalardo, L. L., ~Paremuzyan, R., ~Park, K., ~Pasyuk, E., ~Phelps, W., ~Pogorelko, O., ~Price, J. W., ~Prok, Y., ~Protopopescu, D., ~Ripani, M., Riser, D., ~Rizzo, A., ~Rowley, J., ~Sabatié, F., ~Salgado, C., ~Schumacher, R. A., ~Sharabian, Y. G., ~Shrestha, U., ~Sokhan, D., ~Soto, O., ~Sparveris, N., ~Stepanyan, S., ~Stoler, P., ~Strakovsky, I. I., ~Strauch, S., ~Taiuti, M., ~Tan, J. A., ~Tyler, N., ~Venturelli, L., ~Voskanyan, H., ~Voutier, E., Wang, R., ~Wei, X., ~Wood, M. H., ~Zachariou, N., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Hadronic Physics and QCD, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The exclusive electroproduction process $ep \rightarrow e'p'\pi^{0}$ was measured in the range of photon virtualities $Q^{2} = 0.4 - 1.0$~GeV$^{2}$ and the invariant mass range of the $p\pi^{0}$ system of $W = 1.1 - 1.8$~GeV. These kinematics are covered in exclusive $\pi^{0}$ electroproduction off the proton with nearly complete angular coverage in the $p\pi^{0}$ center-of-mass system and with high statistical accuracy. Nearly 36000 cross section points were measured, and the structure functions $\sigma_T+\epsilon\sigma_L$, $\sigma_{LT}$, and $\sigma_{TT}$, were extracted via fitting the $\phi_{\pi^{0}}$ dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying $N^*$ and $\Delta^{*}$ resonances with $M~>~1.6$ GeV. As part of a broad effort to determine the electrocouplings of the $N^{*}$ and $\Delta^{*}$ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the $N \pi$ and $\pi^{+}\pi^{-} p$ channels., Comment: 21 pages, 24 figures
Published: 2020

15. Photoproduction of $\eta$ mesons off the proton for $1.2 < E_\gamma < 4.7$ GeV using CLAS at Jefferson Laboratory

Author: Hu, T., Akbar, Z., Crede, V., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Carman, D. S., Carvajal, J., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Cruz-Torres, R., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., McCracken, M. E., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: +p+eta%22">photon p --> p eta, health care facilities, manpower, and services, education, rho(770), Regge poles: exchange, Hadronic Physics and QCD, Regge, +pi%2B+pi-+pi0%22">eta --> pi+ pi- pi0, nucleon resonance, eta: photoproduction, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, energy dependence, differential cross section: measured, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], angular distribution, Nuclear Experiment, health care economics and organizations, omega(783), photon: energy, eta: decay modes, coupled channel, vector meson: exchange, biological sciences, High Energy Physics::Experiment, sense organs, spectrometer, experimental results, Jefferson Lab
Abstract: Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to \pi^+\pi^-\pi^0$, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new $\eta$ photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of $\eta$ MAID\,2018 and the latest solution of the Bonn-Gatchina coupled-channel analysis. Differential cross sections $d\sigma/dt$ are presented for incident photon energies $E_\gamma > 2.9$ GeV ($W > 2.5$ GeV), and compared with predictions which are based on Regge trajectories exchange in the $t$-channel (Regge models). The data confirm the expected dominance of $\rho$, $\omega$ vector-meson exchange in an analysis by the Joint Physics Analysis Center., Comment: 24 pages, 22 figures
Published: 2020

16. Physics with Positron Beams at Jefferson Lab 12 GeV

Author: Afanasev, A., Albayrak, I., Ali, S., Amaryan, M., D'Angelo, A., Annand, J., Arrington, J., Asaturyan, A., Avakian, H., Averett, T., Barion, L., Battaglieri, M., Bellini, V., Berdnikov, V., Bernauer, J., Biselli, A., Boer, M., Bond��, M., Brinkmann, K. -T., Briscoe, B., Burkert, V., Camsonne, A., Cao, T., Cardman, L., Carmignotto, M., Causse, L., Celentano, A., Chatagnon, P., Ciullo, G., Contalbrigo, M., Day, D., Defurne, M., Diehl, S., Dongwi, B., Dupr��, R., Dutta, D., Ehrhart, M., Elouadrhiri, L., Ent, R., Fernando, I., Filippi, A., Furletova, Y., Gao, H., Gasparian, A., Gaskell, D., Georges, F., Girod, F. -X., Grames, J., Gu, C., Guidal, M., Hamilton, D., Hasell, D., Higinbotham, D., Hoballah, M., Horn, T., Hyde, C., Italiano, A., Kalantarians, N., Kalicy, G., Keller, D., Keppel, C., Kerver, M., King, P., Kinney, E., Ko, H. -S., Kohl, M., Kubarovsky, V., Lanza, L., Lenisa, P., Liyanage, N., Liuti, S., Mamei, J., Marchand, D., Markowitz, P., Marsicano, L., Mazouz, M., McCaughan, M., McKinnon, B., Mihovilovi��, M., Milner, R., Mkrtchyan, A., Mkrtchyan, H., Movsisyan, A., Camacho, C. Mu��oz, Nadel-Turo��s, P., De Napoli, M., Nazeer, J., Niccolai, S., Niculescu, G., Novotny, R., Pappalardo, L., Paremuzyan, R., Pasyuk, E., Patel, T., Pegg, I., Perera, D., Puckett, A., Randazzo, N., Rashad, M., Rathnayake, M., Rizzo, A., Roche, J., Rondon, O., Schmidt, A., Shabestari, M., Sharabian, Y., ��irca, S., Sokhan, D., Somov, A., Sparveris, N., Stepanyan, S., Strakovsky, I., Tadevosyan, V., Tiefenback, M., Trotta, R., De Vita, R., Voskanyan, H., Voutier, E., Wang, R., Wojtsekhowski, B., Wood, S., Zaunick, H. -G., Zhamkochyan, S., Zhang, J., Zhao, S., Zheng, X., Zorn, C., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: exchange: two-photon, beam: polarization, electroweak interaction, Nuclear Theory, nucleon: form factor: electromagnetic, elastic scattering, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucleon: generalized parton distribution, High Energy Physics - Experiment, positron: beam, High Energy Physics - Experiment (hep-ex), deeply virtual Compton scattering, lepton: accelerator, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), electron: beam, Nuclear Experiment, Jefferson Lab
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental program at the next generation of lepton accelerators. In the context of the Hadronic Physics program at the Jefferson Laboratory (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of the nucleon, in both the elastic and the deep-inelastic regimes. For instance, elastic scattering of (un)polarized electrons and positrons off the nucleon allows for a model independent determination of the electromagnetic form factors of the nucleon. Also, the deeply virtual Compton scattering of (un)polarized electrons and positrons allows us to separate unambiguously the different contributions to the cross section of the lepto-production of photons, enabling an accurate determination of the nucleon Generalized Parton Distributions (GPDs), and providing an access to its Gravitational Form Factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model through the search of a dark photon or the precise measurement of electroweak couplings. This letter proposes to develop an experimental positron program at JLab to perform unique high impact measurements with respect to the two-photon exchange problem, the determination of the proton and the neutron GPDs, and the search for the $A^{\prime}$ dark photon., Letter-of-Intent to Jefferson Lab PAC46
Published: 2019

17. First results on nucleon resonance photocouplings from the $\gamma p \to \pi^+\pi^-p$ reaction

Author: CLAS Collaboration, Golovatch, E., Burkert, V. D., Carman, D. S., Gothe, R. W., Hicks, K., Ishkhanov, B. S., Mokeev, V. I., Pasyuk, E., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Cao, F., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., McKinnon, B., Meyer, C. A., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: B083W, pi: photoproduction, B011W, +pi%2B+pi-+p%22">photon p --> pi+ pi- p, B066.5, B015:Desig=5, B015.5, B083.171, B010A1, B010A2, Nuclear Experiment, B066:Desig=5, resonance: mass, B082:Desig=2, B010.3, B083:Desig=171, B011:Desig=3, B065M, hadron: final state, B065A1, meson: decay, B065A2, B082A1, differential cross section, photoproduction, B082.2, Two pion photoproduction, B065W, B065.5, nucleon resonance, cross section: angular dependence, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], B066M, differential cross section: measured, B065:Desig=5, B010M, B011A1, CLAS, B015A1, B082M, B011A2, Resonance photocouplings, photon: beam, B015A2, B082W, B066W, B010W, B010:Desig=3, B011.3, B011M, Automatic Keywords, B066A1, B015M, Baryon state, B083A2, B083A1, High Energy Physics::Experiment, B015W, B083M, experimental results
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the $\gamma p \to \pi^+\pi^-p$ reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6~GeV~$
Published: 2019

18. First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N∗ Resonance Region

Author: Roy, P., Park, S., Crede, V., Anisovich, A. V., Klempt, E., Nikonov, V. A., Sarantsev, A. V., Wei, N. C., Huang, F., Nakayama, K., Adhikari, K. P., Adhikari, S., Angelini, G., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Burkert, V. D., Cao, F., Carlin, C., Carman, D. S., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Cortes, O., D’Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Duran, B., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fegan, S., Filippi, A., Fradi, A., Gilfoyle, G. P., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joosten, S., Kabir, M. L., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Kunkel, M. C., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I.J.D., Marchand, D., McKinnon, B., Meekins, D. G., Meyer, C. A., Mineeva, T., Mokeev, V., Montgomery, R.A., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Payette, D., Phelps, W., Pierce, J., Pogorelko, O., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Torayev, B., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112))
Subjects: Nuclear Theory, partial wave, Socio-culturale, nucleon resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Photonuclear reactions, Color confinement, Polarization phenomena, QCD in nuclear reactions, Resonance reactions, CLAS, Resonance reactions, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, Nuclear Physics, Settore FIS/04, Polarization phenomena, photon, nucleon, Photonuclear reactions, Color confinement, Automatic Keywords, transverse, QCD in nuclear reactions, polarization: target, Physics::Accelerator Physics, data management, asymmetry, experimental results, Jefferson Lab, photoproduction
Abstract: First measurements of double-polarization observables in $\omega$ photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry $F$ has been measured using circularly polarized, tagged photons in the energy range 1200 - 2700 MeV, and the beam-target asymmetries $H$ and $P$ have been measured using linearly polarized tagged photons in the energy range 1200 - 2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon ($N^\ast$) resonances. In particular, contributions from new $N^\ast$ resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum., Comment: Two authors added, figures updated
Published: 2019

19. Differential Cross Section for $\gamma d \rightarrow \omega d$ using CLAS at Jefferson Lab

Author: Chetry, T., Hicks, K., Compton, N., Sargsian, M., Adhikari, S., Ball, J., Balossino, I., Barion, L., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Carman, D.S., Celentano, A., Charles, G., Ciullo, G., Clark, L., Clary, Brandon A., Cole, P.L., Contalbrigo, M., Crede, V., d'Angelo, A., Dashyan, N., de Vita, R., de Sanctis, E., Deur, A., Djalali, C., Dupre, R., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Giovanetti, K.L., Girod, F.X., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guo, L., Hafidi, K., Harrison, N., Hattawy, M., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Johnston, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, F.J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., Macgregor, I .J .D., Markov, N., Mckinnon, B., Mokeev, V., Movsisyan, A, Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J.W., Prok, Y., Ripani, M., Riser, D., Ritchie, B.G., Rizzo, A., Rosner, G., Salgado, C., Schumacher, R.A., Skorodumina, Iu., Smith, G.D., Sober, D.I., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I.I., Strauch, S., Taiuti, M., Tan, J.A., Ungaro, M., Voskanyan, H., Voutier, E., Weinstein, L.B., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université Paris-Sud - Paris 11 (UP11), and CLAS
Subjects: Vector Meson Dominance, vector dominance, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Double scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], momentum transfer dependence, Single scattering, coherence, High Energy Physics - Experiment, CLAS, differential cross section, +omega%28783%29+deuteron%22">photon deuteron --> omega(783) deuteron, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], omega(783): photoproduction, deuteron: target, High Energy Physics::Experiment, Nuclear Experiment, total cross section, experimental results, Jefferson Lab
Abstract: The cross section for coherent $\omega$-meson photoproduction off the deuteron has been measured for the first time as a function of the momentum transfer $t = (P_{\gamma}-P_{\omega})^2$ and photon energy $E_{\gamma}$ using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are measured in the energy range $1.4 < E_{\gamma} < 3.4$ GeV. A model based on $\omega-N$ rescattering is consistent with the data at low and intermediate momentum transfer, $|t|$. For $2.8 < E_{\gamma} < 3.4$ GeV, the total cross-section of $\omega-N$ scattering, based on fits within the framework of the Vector Meson Dominance model, is in the range of 30-40 mb., Comment: 8 pages, 5 figures
Published: 2018

20. Measurements of the $\gamma_{v} p \rightarrow p' \pi^{+} \pi^{-}$ cross section with the CLAS detector for $0.4$ GeV$^{2}$ $< Q^{2} <$ $1.0$ GeV$^{2}$ and $1.3$ GeV $< W <$ $1.825$ GeV

Author: Fedotov, G.V., Skorodumina, Iu. A., Burkert, V.D., Gothe, R.W., Hicks, K., Mokeev, V.I., Adhikari, S., Armstrong, Whitney R., Avakian, H., Ball, J., Balossino, I., Barion, L., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Carman, D.S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clary, Brandon A., Cole, P.L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., El Fassi, L., Eugenio, P., Fersch, R., Gavalian, G., Ghandilyan, Y., Gilfoyle, G.P., Girod, F.X., Golovatch, E., Griffioen, K.A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jo, H.S., Johnston, S., Joosten, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuleshov, S.V., Lanza, L., Lenisa, P., Livingston, K., Macgregor, I.J.D., Markov, N., Mckinnon, B., Mineeva, T., Montgomery, R.A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Ritchie, B.G., Rizzo, A., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y.G., Smith, G.D., Sober, D.I., Sokhan, D., Sparveris, N., Strakovsky, I.I., Strauch, S., Taiuti, M., Tan, J.A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wei, X., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: meson baryon: interaction, photon, Hadronic Physics and QCD, electroproduction, nucleon resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Automatic Keywords, [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], kinematics, CLAS, quantum chromodynamics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], overlap, High Energy Physics::Experiment, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, statistical, up: mass, meson baryon, experimental results
Abstract: New results on the single-differential and fully-integrated cross sections for the process $\gamma_{v} p \rightarrow p' \pi^{+} \pi^{-}$ are presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the kinematic region of the reaction invariant mass $W$ from 1.3 to 1.825 GeV and the photon virtuality $Q^2$ from 0.4 to 1.0 GeV$^2$. The cross sections were obtained in narrow $Q^{2}$ bins (0.05 GeV$^{2}$) with the smallest statistical uncertainties achieved in double-pion electroproduction experiments to date. The results were found to be in agreement with previously available data where they overlap. A preliminary interpretation of the extracted cross sections, which was based on a phenomenological meson-baryon reaction model, revealed substantial relative contributions from nucleon resonances. The data offer promising prospects to improve knowledge on the $Q^{2}$-evolution of the electrocouplings of most resonances with masses up to $\sim$1.8 GeV., Comment: 22 pages, 22 figures, will be sent to Phys. Rev. C
Published: 2018

21. Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the $A(e,e′pp)$ Reaction

Author: Cohen, E.O., Hen, O., Piasetzky, E., Weinstein, L.B., Schmidt, A., Hakobyan, H., Adhikari, S., Akbar, Z., Amaryan, M.J., Avakian, H., Ball, J., Barion, L., Battaglieri, M., Beck, A., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W., Burkert, V.D., Cao, F., Carman, D.S., Celentano, A., Charles, G., Chatagnon, Pierre, Chetry, T., Ciullo, G., Clary, Brandon A., Contalbrigo, M., Crede, V., Cruz Torres, R., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Duer, M., Dupre, R., Egiyan, H., Ehrhart, Mathieu, El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Giovanetti, K.L., Girod, F.X., Golovatch, E., Gothe, R.W., Griffioen, K.A., Hafidi, K., Harrison, N., Hauenstein, F., Heddle, D., Hicks, K., Holtrop, M., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jo, H.S., Johnston, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Korover, I., Kubarovsky, V., Kuhn, S.E., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I .J .D., Marchand, D., Mckinnon, B., Mey-Tal Beck, S., Meyer, C.A., Mirazita, M., Mokeev, V., Montgomery, R.A., Movsisyan, A, Munoz Camacho, C., Mustapha, B., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Pasyuk, E., Pogorelko, O., Price, J.W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Schmookler, B.A., Schumacher, R.A., Sharabian, Y.G., Sokhan, D., Sparveris, N., Stepanyan, S., Strauch, S., Taiuti, M., Tan, J.A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D.P., Wei, X., Wood, M.H., Zachariou, N., Zhang, J., Zheng, X., Zhao, Z.W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Nuclear Theory (nucl-th), Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nuclear Physics
Abstract: Short-Range Correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (kF). A fundamental characteristic of SRC pairs is having large relative momenta as compared to kF, and smaller center-of-mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in Carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e'pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states., Accepted to PRL. 7 pages, 3 figures
Published: 2018

22. Measurement of the ${Q}^{2}$ Dependence of the Deuteron Spin Structure Function ${g}_{1}$ and its Moments at Low ${Q}^{2}$ with CLAS

Author: Adhikari, K. P., Deur, A., El Fassi, L., Kang, H., Kuhn, S. E., Ripani, M., Slifer, K., Zheng, X., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Balossino, I., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Bosted, P., Briscoe, W. J., Brock, J., Bültmann, S., Burkert, V. D., Thanh Cao, F., Carlin, C., Carman, D. S., Celentano, A., Charles, G., Chen, J.-P., Chetry, T., Choi, S., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Djalali, C., Dodge, G. E., Drozdov, V., Dupre, R., Egiyan, H., El Alaoui, A., Elouadrhiri, L., Eugenio, P., Fedotov, G., Filippi, A., Ghandilyan, Y., Gilfoyle, G. P., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S. C., Joo, K., Joosten, S., Kabir, M. L., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Konczykowski, P., Kovacs, K., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., Long, E., MacGregor, I. J. D., Markov, N., Mayer, M., McKinnon, B., Meekins, D. G., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niculescu, G., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L., Paremuzyan, R., Park, K., Pasyuk, E., Payette, D., Phelps, W., Phillips, S. K., Pierce, J., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Shigeyuki, T., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sparveris, N., Sokhan, D., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sulkosky, V., Taiuti, M., Tan, J. A., Ungaro, M., Voutier, E., Wei, X., Weinstein, L. B., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: photonuclear reactions, Socio-culturale, polarized target, FOS: Physical sciences, Strong interaction, structure function: spin, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 25.30.Rw, Settore FIS/04 - Fisica Nucleare e Subnucleare, magnetic moments, Physics and Astronomy (all), benchmark, spin: polarizability, Chiral perturbation theory, CLAS, quantum chromodynamics, Nuclear Experiment (nucl-ex), Nuclear Experiment, polarization, Polarization phenomena, High Energy Physics::Phenomenology, 11.55.Hx, deuteron: structure function, perturbation theory: chiral, QCD in nuclear reactions, proton scattering, magnetic moments, polarized target, photonuclear reactions, Chiral perturbation theory, Lepton induced nuclear reactions, Polarization phenomena, Strong interaction, moment, Automatic Keywords, deuteron: spin, QCD in nuclear reactions, Lepton induced nuclear reactions, 12.38.Qk, proton scattering, Drell-Hearn-Gerasimov, High Energy Physics::Experiment, 13.60.Hb, experimental results
Abstract: We measured the $g_1$ spin structure function of the deuteron at low $Q^{2}$, where QCD can be approximated with chiral perturbation theory ($\chi$PT). The data cover the resonance region, up to an invariant mass of $W\approx1.9$~GeV. The generalized Gerasimov-Drell-Hearn sum, the moment $\bar{\Gamma}_{1}^{d}$ and the integral $\bar{I}_\gamma^d$ related to the spin polarizability $\gamma_{0}^{d}$ are precisely determined down to a minimum $Q^2$ of 0.02~GeV$^2$ for the first time, about 2.5 times lower than that of previous data. We compare them to several $\chi$PT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the $\chi$PT domain., Comment: Version 1: version published in Phys. Rev. Lett. 6 pages, 3 figures. Supplementary material: data table for g1d and its moments (10 pages) V2: Figures labels changed and text slightly modified to clarify the exact nature of the measured moments V3: Corrected a typo page 5 for the theoretical value expected for deuteron GDH sum rule (agreement between measurement and expectation is improved)
Published: 2018

23. Measurement of the beam asymmetry $\Sigma$ and the target asymmetry $T$ in the photoproduction of $\omega$ mesons off the proton using CLAS at Jefferson Laboratory

Author: Roy, P., Akbar, Z., Park, S., Crede, V., Anisovich, A.V., Denisenko, I., Klempt, E., Nikonov, V.A., Sarantsev, A.V., Adhikari, K.P., Adhikari, S., Anefalos Pereira, S., Ball, J., Balossino, I., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W.J., Brock, J., Brooks, W.K., Burkert, V.D., Carlin, C., Carman, D.S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clary, B.A., Cole, P.L., Contalbrigo, M., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dugger, M., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fradi, A., Gavalian, G., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Hattawy, M., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Joo, K., Joosten, S., Keith, C.D., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuleshov, S.V., Lanza, L., Lenisa, P., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Markov, N., Mayer, M., Mccracken, M.E., Mckinnon, B., Meekins, D.G., Meyer, C.A., Meziani, Z.E., Mineeva, T., Mokeev, V., Montgomery, R.A., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A.I., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, E., Phelps, W., Pierce, J.J., Pogorelko, O., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B.A., Ripani, M., Riser, D., Ritchie, B.G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y.G., Skorodumina, Iu., Smith, G.D., Sober, D.I., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I.I., Strauch, S., Taiuti, M., Tan, J.A., Torayev, B., Ungaro, M., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), CLAS, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: pomeron: exchange, beam: polarization, accelerator, helicity: asymmetry, partial wave analysis, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], photon: energy spectrum, meson, High Energy Physics - Experiment, Automatic Keywords, beam: asymmetry, meson: photoproduction, meson: exchange, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], n: target, High Energy Physics::Experiment, target: asymmetry, data management, Nuclear Experiment, experimental results, resonance: production, photoproduction
Abstract: The photoproduction of $\omega$ mesons off the proton has been studied in the reaction $\gamma p\to p\,\omega$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry, $T$, has been measured in photoproduction from the decay $\omega\to\pi^+\pi^-\pi^0$, using a transversely-polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant non-zero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry, $\Sigma$, are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional $\omega$-photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from $s$-channel resonance production were found in addition to $t$-channel exchange processes., Comment: 15 pages, 10 figures, author list and references updated
Published: 2018

24. Beam-target helicity asymmetry $E$ in $K^{0}\Lambda$ and $K^{0}\Sigma^0$ photoproduction on the neutron

Author: Ho, D.H., Schumacher, R.A., d'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Klein, F.J., Klempt, E., Lowry, M.M., Lu, H., Nikonov, V.A., Peng, P., Sandorfi, A.M., Sarantsev, A.V., Strakovsky, I.I., Walford, N.K., Wei, X., Workman, R.L., Adhikari, K.P., Adhikari, S., Adikaram, D., Akbar, Z., Ball, J., Barion, L., Bashkanov, M., Bass, C.D., Battaglieri, M., Bedlinskiy, I., Biselli, A.S., Briscoe, W.J., Boiarinov, S., Burkert, V.D., Cao, F., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B.A., Cole, P., Collins, P., Contalbrigo, M., Crede, V., de Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Giovanetti, K.L., Girod, F.X., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jo, H.S., Johnston, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Laine, V., Lanza, L., Lenisa, P., Livingston, K., Macgregor, I.. J . D., Marchand, D., Markov, N., Mayer, M., Mckinnon, B., Meyer, C.A., Mirazita, M., Mokeev, V., Montgomery, R.A., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J.W., Prok, Y., Protopopescu, D., Rehfuss, M., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Sharabian, Y.G., Skorodumina, Iu., Smith, G.D., Sober, D.I., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Tan, J.A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D.P., Weinstein, L.B., Whisnant, C.S., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Zonta, I., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), CLAS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear Theory, Hadronic Physics and QCD, helicity: asymmetry, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], beam: asymmetry, isospin, Automatic Keywords, solids, background: low, pseudoscalar meson: photoproduction, CLAS, hydrogen, differential cross section, n: target, isospin: dependence, Nuclear Experiment, photon: beam, experimental results, hydrogen: target, Jefferson Lab
Abstract: We report the first measurements of the $E$ beam-target helicity asymmetry for the $\vec{\gamma} \vec{n} \to K^{0}\Lambda$, and $K^{0}\Sigma^{0}$ channels in the energy range 1.70$\leq W\leq$2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees was used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin $I=0$ and $I=1$ photo-coupling transition amplitudes in pseudoscalar meson photoproduction., Comment: 14 pages, 9 figures; Revised to match published version
Published: 2018

25. Exclusive η electroproduction at W > 2 GeV with CLAS and transversity generalized parton distributions

Author: CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Stoler, P., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Hughes, S. M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Turisini, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yurov, M., Zachariou, N., Zhang, J., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, University of Ca’ Foscari [Venice, Italy], Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre d'Etude et de Recherche des Phosphates Minéraux, CERPHOS, R&D, Climespace, University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), Autre, non renseigné, Department of Computer Science [Oxford], University of Oxford [Oxford], University of Southampton, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Tsukuba University of Technology, CLASS collaboration, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Department of computer science, University of Oxford, University of Oxford, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Phenomenology, High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, High Energy Physics - Experiment
Abstract: The cross section of the exclusive $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\eta$ and structure functions $\sigma_U = \sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$, as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The $\eta$ structure functions are compared with those previously measured for $\pi^0$ at the same kinematics. At low $t$, both $\pi^0$ and $\eta$ are described reasonably well by generalized parton distributions (GPDs) in which chiral-odd transversity GPDs are dominant. The $\pi^0$ and $\eta$ data, when taken together, can facilitate the flavor decomposition of the transversity GPDs., Comment: 16 pages, 16 figures
Published: 2017

26. Target and beam-target spin asymmetries in exclusive pion electroproduction for Q 2 > 1 GeV 2 . II. e p → e π 0 p

Author: Bosted, E., Kim, A., Adhikari, P., Adikaram, D., Akbar, Z., Amaryan, J., Anefalos Pereira, S., Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, S., Boiarinov, S., Briscoe, J., Brooks, W., Bültmann, S., Burkert, D., Cao, T., Carman, S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J., Forest, A., Fradi, A., Ghandilyan, Y., Gilfoyle, P., Girod, X., Glazier, I., Gohn, W., Golovatch, E., Gothe, W., Griffioen, A., Guidal, M., Guler, N., Hakobyan, H., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, M., Ireland, D., Isupov, E., Jenkins, D., Jiang, H., Jo, H., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klei, A., Klein, J., Koirala, S., Kubarovsky, V., Kuhn, Estelle, Lanza, L., Lenisa, P., Livingston, K., Lu, H., MacGregor, I., Markov, N., Mayer, M., McCracken, E., Mckinnon, B., Mineeva, T., Mirazita, M., Mokeev, I., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J., Prok, Y., Protopopescu, D., Puckett, J., Raue, B., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, Pascal, Sabatié, F., Saini, M., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Stoler, P., Strakovsky, I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zhang, J., Zhao, Z. W., Zonta, I., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and CLAS Collaboration
Subjects: High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π0 electroproduction reaction γ∗p→pπ0, expanding an analysis of the γ∗p→nπ+ reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1
Published: 2017

27. Measurement of the differential and total cross sections of the ${\gamma}d{\rightarrow}{K}^{0}\mathrm{{\Lambda}}(p)$ reaction within the resonance region

Author: Compton, N., Taylor, C.E., Hicks, K., Zachariou, N., Ilieva, Y., Klempt, E., Nikonov, V.A., Sarantsev, A.V., Adhikari, K.P., Adhikari, S., Akbar, Z., Anefalos Pereira, S., Avakian, H., Baltzell, N.A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Camp, M., Cao, Frank Thanh, Cao, T., Carman, D.S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Filippi, A., Fleming, J.A., Fradi, A., Gavalian, G., Ghandilyan, Y., Giovanetti, K.L., Girod, F.X., Glazier, D.I., Gleason, C., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Holtrop, M., Hughes, S.M., Hyde, C.E., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuleshov, S.V., Lanza, L., Lenisa, P., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Markov, N., Mckinnon, B., Meyer, C.A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R.A., Movsisyan, A., Munevar, E., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J.W., Prok, Y., Protopopescu, D., Raue, B.A., Ripani, M., Ritchie, B.G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y.G., Simonyan, A., Skorodumina, Iu., Smith, G.D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I.I., Strauch, S., Taiuti, M., Torayev, B., Trivedi, A., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Wood, M.H., Zhang, J., Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), and Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay
Subjects: deuteron, p: spectator, Regge, K+: production, nucleon resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], bremsstrahlung, tagged beam, Lambda: production, CLAS, deuterium: target, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], momentum: correction, Nuclear Experiment, numerical calculations, Monte Carlo, photon: beam, total cross section, partial wave analysis, gamma ray, differential cross section, High Energy Physics::Experiment, pi+ pi, particle identification, missing-mass, 0.8-3.6 GeV0.5-2.6 GeV, experimental results, Jefferson Lab, photoproduction
Abstract: International audience; We report the first measurement of differential and total cross sections for the γd→K0Λ(p) reaction, using data from the CLAS detector at the Thomas Jefferson National Accelerator Facility. Data collected during two separate experimental runs were studied with photon-energy coverage 0.8–3.6 GeV and 0.5– 2.6 GeV, respectively. The two measurements are consistent giving confidence in the method and determination of systematic uncertainties. The cross sections are compared with predictions from the KAON-MAID theoretical model (without kaon exchange), which deviate from the data at higher W and at forward kaon angles. These data, along with previously published cross sections for K+Λ photoproduction, provide essential constraints on the nucleon resonance spectrum. A first partial wave analysis was performed that describes the data without the introduction of new resonances.
Published: 2017

28. Photon beam asymmetry $\Sigma$ for $\eta$ and $\eta^\prime$ photoproduction from the proton

Author: Collins, P., Ritchie, B. G., Dugger, M., Anisovich, A. V., Döring, M., Klempt, E., Nikonov, V. A., Rönchen, D., Sadasivan, D., Sarantsev, A., Adhikaria, K. P., Akbar, Z., Amaryana, M. J., Pereira, S. Anefalos, Avakiana, H., Ball, J., Balossino, I., Bashkanova, M., Battaglieri, M., Bedlinskiy, I., Bisellik, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, Frank Thanh, Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wei, X., Zachariou, N., Zhang, J., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: polarized beam, nucleon resonance, eta: photoproduction, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], bremsstrahlung: coherence, tagged beam, pi: background, helicity: coupling, 4.55 GeV1.070-1.876 GeV1.516-1.836 GeV, Eta-prime photoproduction, CLAS, Eta photoproduction, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, photon: beam, hydrogen: target, Meson photoproduction, Polarization observable, beam: asymmetry, meson: photoproduction, missing-mass: spectrum, eta(958): photoproduction, cryogenics, drift chamber, High Energy Physics::Experiment, Photon beam asymmetry, particle identification, experimental results, Jefferson Lab
Abstract: Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $\gamma p \to \eta p$ reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the $\gamma p \to \eta^\prime p$ reaction. For $\gamma p \to \eta p$, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For $\gamma p \to \eta^\prime p$, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn-Gatchina model strengthens the evidence for four nucleon resonances -- the $N(1895)1/2^-$, $N(1900)3/2^+$, $N(2100)1/2^+$ and $N(2120)3/2^-$ resonances -- which presently lack the "four-star" status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process., Comment: 10 pages, 3 figures
Published: 2017

29. Photon beam asymmetry $\Sigma$ in the reaction $\vec{\gamma} p \to p \omega$ for $E_\gamma$ = 1.152 to 1.876 GeV

Author: CLAS Collaboration, Collins, P., Ritchie, B. G., Dugger, M., Klein, F. J., Anisovich, A. V., Klempt, E., Nikonov, V. A., Sarantsev, A., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, Frank Thanh, Cao, T., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Filippi, A., Fleming, J. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: interference, nucleon resonance, polarized beam, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], bremsstrahlung, chiral quark soliton model, tagged beam, CLAS, meson: exchange, 14.20.Gk, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, photon: beam, hydrogen: target, pomeron: exchange, polarization observable, 1.152-1.876 GeV, partial wave analysis, beam asymmetry, model: coupled channel, meson photoproduction, beam: asymmetry, Omega photoproduction, meson: photoproduction, 14.20.Dh, data management, particle identification, 13.60.Le, experimental results, Jefferson Lab
Abstract: Photon beam asymmetry $\Sigma$ measurements for $\omega$ photoproduction in the reaction $\vec{\gamma} p \to \omega p$ are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between $t$-channel meson exchange and $s$- and $u$-channel contributions, underscoring sensitivity to the nucleon resonances included in those descriptions. Comparisons with the Bonn-Gatchina partial-wave analysis indicate the $\Sigma$ data reported here help to fix the magnitudes of the interference terms between the leading amplitudes in that calculation (Pomeron exchange and the resonant portion of the $J^P=3/2^+$ partial wave), as well as the resonant portions of the smaller partial waves with $J^P$= $1/2^-$, $3/2^-$, and $5/2^+$., Comment: 10 pages, 3 figures
Published: 2017

30. Determination of the proton spin structure functions for $0.05<{Q}^{2}<5{\mathrm{GeV}}^{2}$ using CLAS

Author: Fersch, Robert, Guler, Nevzat, Bosted, Peter, Deur, Alexandre, Griffioen, Keith, Keith, Christopher, Kuhn, Sebastian, Minehart, Ralph, Prok, Yelena, Adhikari, K. P., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Asryan, G., Avakian, H., Ball, J., Balossino, A., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Bultmann, S., Burkert, V. D., Thanh Cao, Frank, Carman, D. S., Careccia, S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, A., Filippi, A., Fleming, J. A., Forest, T. A., Garc con, M., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S.M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Joo, K., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Lagerquist, V. G., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., Mckinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Weinstein, L.B., Zachariou, N., Zhang, J., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: Born approximation, electron: polarized beam, elastic scattering, structure function: spin, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], photon: asymmetry, microwaves, duality: quark hadron, p: target, p: spin, 13.88.+e, CLAS, deep inelastic scattering, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, hydrogen: target, background, 1.6 GeV2.5 GeV4.2 GeV5.7 GeV, inelastic scattering, moment, nucleon structure, 14.20.Dh, High Energy Physics::Experiment, deuteron: target, quark: polarization, absorption, spin: asymmetry, 13.60.Hb, experimental results, Jefferson Lab, photon: virtual
Abstract: International audience; We present the results of our final analysis of the full data set of g1p(Q2), the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000–2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets (NH315 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries A1p and A2p and spin structure functions g1p and g2p over a wide kinematic range (0.05 GeV2
Published: 2017

31. Differential cross section measurements for $\gamma n\rightarrow{\pi}^{-}p$ above the first nucleon resonance region

Author: Mattione, P.T., Carman, D.S., Strakovsky, I.I., Workman, R.L., Kudryavtsev, A.E., Svarc, A., Tarasov, V.E., Adhikari, K.P., Adhikari, S., Adikaram, D., Akbar, Z., Anefalos Pereira, S., Ball, J., Baltzell, N.A., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W.J., Burkert, V.D., Cao, T., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J.A., Fradi, A., Ghandilyan, Y., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Gleason, C., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S.M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jiang, H., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuleshov, S.V., Lanza, L., Lenisa, P., Livingston, K., Macgregor, I.J.D., Markov, N., Mckinnon, B., Meyer, C.A., Meziani, Z.E., Mineeva, T., Mokeev, V., Montgomery, R.A., Movsisyan, A, Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Net, L.A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B.A., Ripani, M., Ritchie, B.G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y.G., Simonyan, A., Skorodumina, Iu., Smith, G.D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D, Wei, X., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: N(1720), Astrophysics::High Energy Astrophysical Phenomena, nucleon resonance, momentum, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, pi-: photoproduction, tagged beam, bremsstrahlung, CLAS, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], electron: beam, Nuclear Experiment, numerical calculations, photon: beam, photon: decay, resonance: pole, K-matrix, N(1440), N(1650), 0.445-2.510 GeV, N(1535), final-state interaction, differential cross section, High Energy Physics::Experiment, deuteron: target, particle identification, Jefferson Lab, experimental results
Abstract: The quasi-free $\gamma d\to\pi^{-}p(p)$ differential cross section has been measured with CLAS at photon beam energies $E_\gamma$ from 0.445 GeV to 2.510 GeV (corresponding to $W$ from 1.311 GeV to 2.366 GeV) for pion center-of-mass angles $\cos\theta_\pi^{c.m.}$ from -0.72 to 0.92. A correction for final state interactions has been applied to this data to extract the $\gamma n\to\pi^-p$ differential cross sections. These cross sections are quoted in 8428 $(E_\gamma,\cos\theta_\pi^{c.m.})$ bins, a factor of nearly three increase in the world statistics for this channel in this kinematic range. These new data help to constrain coupled-channel analysis fits used to disentangle the spectrum of $N^*$ resonances and extract their properties. Selected photon decay amplitudes $N^* \to \gamma n$ at the resonance poles are determined for the first time and are reported here.
Published: 2017

32. Determination of the Proton Spin Structure Functions for $0.05 < Q^{2} < 5 GeV^{2}$ using CLAS

Author: Fersch, Robert, Guler, Nevzat, Bosted, Peter, Deur, Alexandre, Griffioen, Keith, Keith, Christopher, Kuhn, Sebastian, Minehart, Ralph, Prok, Yelena, Adhikari, K. P., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Asryan, G., Avakian, H., Ball, J., Balossino, A., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Bultmann, S., Burkert, V. D., Thanh Cao, Frank, Carman, D. S., Careccia, S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, A., Filippi, A., Fleming, J. A., Forest, T. A., Garc con, M., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S.M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Joo, K., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Lagerquist, V. G., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., Mckinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Weinstein, L.B., Zachariou, N., Zhang, J., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Born approximation, electron: polarized beam, elastic scattering, structure function: spin, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], photon: asymmetry, duality: quark hadron, microwaves, p: target, p: spin, 13.88.+e, deep inelastic scattering, CLAS, Nuclear Experiment, hydrogen: target, background, 1.6 GeV2.5 GeV4.2 GeV5.7 GeV, inelastic scattering, moment, nucleon structure, 14.20.Dh, High Energy Physics::Experiment, deuteron: target, quark: polarization, 13.60.Hb, spin: asymmetry, absorption, photon: virtual, Jefferson Lab, experimental results
Abstract: We present the results of our final analysis of the full data set of g_1^p(Q^2), the spin structure function of the proton, collected using CLAS at Jefferson Lab in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.7 GeV were scattered from proton targets (15^NH_3 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries A_1^p and A_2^p and spin structure functions g_1^p and g_2^p over a wide kinematic range (0.05 GeV^2 < Q^2 < 5 GeV^2 and 1.08 GeV < W < 3 GeV), and calculated moments of g_1^p. We compare our final results with various theoretical models and expectations, as well as with parameterizations of the world data. Our data, with their precision and dense kinematic coverage, are able to constrain fits of polarized parton distributions, test pQCD predictions for quark polarizations at large x, offer a better understanding of quark-hadron duality, and provide more precise values of higher-twist matrix elements in the framework of the Operator Product Expansion., Comment: 38 pages, 40 figures
Published: 2017

33. Measurements of $e p \to e' \pi^+ \pi^- p'$ Cross Sections with CLAS at $1.40$ Gev $< W < 2.0$ GeV and $2.0$ GeV$^2$ $< Q^2 < 5.0$ GeV$^2$

Author: Isupov, E.L., Burkert, V.D., Carman, D.S., Gothe, R.W., Hicks, K., Ishkhanov, B.S., Mokeev, V.I., Adhikari, K.P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M.J., Anefalos Pereira, S., Avakian, H., Ball, J., Baltzell, N.A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Briscoe, W.J., Brooks, W.K., Bültmann, S., Cao, T., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J.A., Forest, T.A., Garçon, M., Gavalian, G., Ghandilyan, Y., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Glazier, D.I., Gleason, C., Golovatch, E., Griffioen, K.A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Hughes, S.M., Ilieva, Y., Ireland, D.G., Jenkins, D., Jiang, H., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuleshov, S.V., Kunkel, M., Lanza, L., Lenisa, P., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Markov, N., Mckinnon, B., Mineeva, T., Mirazita, M., Montgomery, R.A., Movsisyan, A., Munevar, E., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B.A., Ripani, M., Riser, D., Ritchie, B.G., Rizzo, A., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y.G., Simonyan, A., Skorodumina, Iu., Smith, G.D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I.I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Trivedi, A., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Wei, X., Wood, M.H., Zachariou, N., Zhang, J., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS, Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: +electron+pi%2B+pi-+p%22">electron p --> electron pi+ pi- p, 13.40.Gp, meson: electroproduction, photon, 11.55.Fv, nucleon resonance, Newport News CEBAF Linac, cross section: measured, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Breit-Wigner, pi+ pi-: interaction, Dyson-Schwinger equation, error: statistical, pi-: final state, kinematics, CLAS, differential cross section, 14.20.Gk, 1.4-2.0 GeV-cms, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], electron p, numerical calculations, 13.60.Le, experimental results
Abstract: International audience; This paper reports new exclusive cross sections for ep→e′π+π−p′ using the CLAS detector at Jefferson Laboratory. These results are presented for the first time at photon virtualities 2.0GeV2
Published: 2017

34. Beam-Target Helicity Asymmetry for $\vec{\gamma} \vec{n} \rightarrow \pi^- p$ in the $N^*$ Resonance Region

Author: Ho , D., Peng , P., Bass , C., Collins , P., D'Angelo , A., Deur , A., Fleming , J., Hanretty , C., Kageya , T., Khandaker , M., Klein , F.J., Klempt , E., Laine , V., Lowry , M.M., Lu , H., Nepali , C., Nikonov , V.A., O'Connell , T., Sandorfi , A.M., Sarantsev , A.V., Schumacher , R.A., Strakovsky , I.I., $v{S}varc , A., Walford , N.K., Wei , X., Whisnant , C.S., Workman , R.L., Zonta , I., Adhikari , K.P., Adikaram , D., Akbar , Z., Amaryan , M.J., Anefalos Pereira , S., Avakian , H., Ball , J., Bashkanov , M., Battaglieri , M., Batourine , V., Bedlinskiy , I., Biselli , A., Briscoe , W.J., Burkert , V.D., Carman , D.S., Celentano , A., Charles , G., Chetry , T., Ciullo , G., Clark , L., Colaneri , L., Cole , P.L., Contalbrigo , M., Crede , V., Dashyan , N., De Sanctis , E., De Vita , R., Djalali , C., Dupre , R., El Alaoui , A., El Fassi , L., Elouadrhiri , L., Eugenio , P., Fedotov , G., Fegan , S., Fersch , R., Filippi , A., Fradi , A., Ghandilyan , Y., Gilfoyle , G.P., Girod , F.X., Glazier , D.I., Gleason , C., Gohn , W., Golovatch , E., Gothe , R.W., Griffioen , K.A., Guidal , M., Guo , L., Hakobyan , H., Harrison , N., Hattawy , M., Hicks , K., Holtrop , M., Hughes , S.M., Ilieva , Y., Ireland , D.G., Ishkhanov , B.S., Isupov , E.L., Jenkins , D., Jiang , H., Jo , H.S., Joo , K., Joosten , S., Keller , D., Khachatryan , G., Kim , A., Kim , W., Klein , A., Kubarovsky , V., Kuleshov , S.V., Lanza , L., Lenisa , P., Livingston , K., MacGregor , I, Markov , N., Mckinnon , B., Mineeva , T., Mokeev , V., Montgomery , R.A., Movsisyan , A, Munoz Camacho , C., Murdoch , G., Niccolai , S., Niculescu , G., Osipenko , M., Paolone , M., Paremuzyan , R., Park , K., Pasyuk , E., Phelps , W., Pogorelko , O., Price , J.W., Procureur , S., Protopopescu , D., Ripani , M., Riser , D., Ritchie , B.G., Rizzo , A., Rosner , G., Sabati$^'e , F., Salgado , C., Sharabian , Y.G., Skorodumina , Iu., Smith , G.D., Sober , D.I., Sokhan , D., Sparveris , N., Strauch , S., Tian , Ye, Torayev , B., Ungaro , M., Voskanyan , H., Voutier , E., Watts , D.P., Wood , M.H., Zachariou , N., Zhang , J., Zhao , Z.W., Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont ( LPC ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: 25.20.Lj, deuteron, partial wave, nucleon resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], isospin, 13.88.+e, CLAS, 14.20.Gk, quantum chromodynamics, n: target, vertex, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, numerical calculations, Monte Carlo, polarization, photon, helicity: asymmetry, final-state interaction, resonance, kinematics, W: mass, +pi-+p%22">photon n --> pi- p, 13.60.Le, Jefferson Lab
Abstract: We report the first beam-target double-polarization asymmetries in the $\gamma + n(p) \rightarrow \pi^- + p(p)$ reaction spanning the nucleon resonance region from invariant mass $W$= $1500$ to $2300$ MeV. Circularly polarized photons and longitudinally polarized deuterons in $H\!D$ have been used with the CLAS detector at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the {\it{E}} polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses, and have led to significant revisions for several $\gamma nN^*$ resonance photo-couplings., Comment: 6 pages, 5 figures; Physical Review Letters - in press
Published: 2017

35. First Exclusive Measurement of Deeply Virtual Compton Scattering off $^4$He: Toward the 3D Tomography of Nuclei

Author: Hattawy, M., Baltzell, N. A., Dupré, R., Hafidi, K., Stepanyan, S., Bültmann, S., De Vita, R., El Alaoui, A., El Fassi, L., Egiyan, H., Girod, F. X., Guidal, M., Jenkins, D., Liuti, S., Perrin, Y., Torayev, B., Voutier, E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Armstrong, Whitney R., Avakian, H., Ball, J., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Thanh Cao, Frank, Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D’Angelo, A., Dashyan, N., De Sanctis, E., Deur, A., Djalali, C., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, H., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique Subatomique et de Cosmologie ( LPSC ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
Subjects: Nuclear Theory, FOS: Physical sciences, Socio-culturale, Bethe-Heitler, helium, Newport News CEBAF Linac, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], PHOTONS, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment (hep-ex), [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], GENERALIZED PARTON DISTRIBUTIONS, deeply virtual Compton scattering, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], electron: beam, Nuclear Experiment, mesons, nucleus: recoil, Generalized parton distributions, electroproduction, photons, mesons, Bjorken, ELECTROPRODUCTION, Compton scattering: form factor, helicity, time projection chamber, calorimeter: electromagnetic, 6 GeV, kinematics, coherent interaction, Physics::Accelerator Physics, particle identification, momentum: low, experimental results, Jefferson Lab
Abstract: We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized \ud 4\ud He\ud gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling \ud 4\ud He\ud nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only \ud 4\ud He\ud Compton form factor, \ud H\ud A\ud . This first measurement of coherent deeply virtual Compton scattering on the \ud 4\ud He\ud nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.
Published: 2017

36. Photoproduction of $\Lambda$ and $\Sigma^0$ hyperons using linearly polarized photons

Author: Paterson, C. A., Ireland, D. G., Livingston, K., Mckinnon, B., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M., Anefalos Pereira, S., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., d'Angelo, A., de Vita, R., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Lu, H. Y., Macgregor, I. J. D., Markov, N., Mattione, P., Mayer, C. A., Mccracken, M. E., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, Pascal, Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Torayev, B., Tucker, R., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Zachariou, N., Zana, L., Zhang, J., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and CLAS Collaboration
Subjects: Beam, bremsstrahlung, observables, Socio-culturale, Beam, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, bremsstrahlung, observables
Abstract: Background: Measurements of polarization observables for the reactions $\vec{\gamma} p \rightarrow K^+ \Lambda$ and $\vec{\gamma} p \rightarrow K^+ \Sigma^0$ have been performed. This is part of a programme of measurements designed to study the spectrum of baryon resonances. Purpose: The accurate measurement of several polarization observables provides tight constraints for phenomenological fits. Beam-recoil observables for the $\vec{\gamma} p \rightarrow K^+ \Sigma^0$ reaction have not been reported before now. Method: The measurements were carried out using linearly polarized photon beams and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71\,GeV $, Comment: 29 pages, 13 figures
Published: 2016

37. Measurement of target and double-spin asymmetries for the e ⃗ p ⃗ → e π + ( n ) reaction in the nucleon resonance region at low Q 2

Author: Zheng, X., Adhikari, P., Bosted, P., Deur, A., Drozdov, V., El Fassi, L., Kang, Hyekoo, Kovacs, K., Kuhn, S., Long, E., Phillips, S., Ripani, M., Slifer, K., Smith, C., Adikaram, D., Akbar, Z., Amaryan, J., Anefalos Pereira, S., Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, S., Briscoe, J., Bültmann, S., Burkert, D., Carman, S., Celentano, A., Chandavar, S., Charles, G., Chen, Jie, Chetry, T., Choi, Seonho, Ciullo, G., Clark, L., Colaneri, L., Cole, P., Compton, N., Contalbrigo, M., Crede, V., d'Angelo, A., Dashyan, N., de Vita, R., de Sanctis, E., Djalali, C., Dodge, E., Dupre, R., Egiyan, H., El Alaoui, A., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, P., Giovanetti, K., Girod, X., Gleason, C., Golovach, E., Gothe, R., Griffioen, A., Guidal, M., Guler, N., Guo, L., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, M., Ilieva, Y., Ireland, D., Ishkhanov, S., Isupov, E., Jenkins, D., Jiang, H., Jo, H., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., Macgregor, I., Markov, N., Mckinnon, B., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Net, A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J., Puckett, J., Raue, A., Rizzo, A., Rosner, G., Rossi, P., Roy, Pascal, Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I., Strauch, S., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zhang, J., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS Collaboration, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models., Comment: 20 pages, 15 figures, to appear in Phys. Rev. C
Published: 2016

38. Target and beam-target spin asymmetries in exclusive π + and π − electroproduction with 1.6- to 5.7-GeV electrons

Author: Bosted, P. E., Biselli, A. S., Careccia, S., Dodge, G., Fersch, R., Guler, N., Kuhn, S. E., Pierce, J., Prok, Y., Zheng, X., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., McCracken, M. E., McKinnon, B., Meyer, C. A., Minehart, R., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sparveris, N., Stankovic, Ivana, Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CLAS Collaboration, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Nuclear and High Energy Physics, Economica, Socio-culturale, Ambientale, High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, QC
Abstract: Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $\pi^+$ and $\pi^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $\pi^+$) and deuterons (for $\pi^-$) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is $1.11.5$ GeV. Very large target-spin asymmetries are observed for $W>1.6$ GeV. When combined with cross section measurements, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of $Q^2$, for resonances with masses as high as 2.3 GeV., Comment: 47 pages, 24 figures. This is a revised version that was accepted for publication in Phys. Rev. C. in early October, 2016
Published: 2016

39. Photoproduction of and 0 hyperons using linearly polarized photons

Author: Paterson, C. A., Ireland, D. G., Livingston, K., Mckinnon, B., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M., Anefalos Pereira, S., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., De Vita, R., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mattione, P., Mayer, C. A., McCracken, M. E., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, Pascal, Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Torayev, B., Tucker, R., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Zachariou, N., Zana, L., Zhang, J., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and CLAS Collaboration
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; Background: Measurements of polarization observables for the reactions γ p → K + and γ p → K + 0 have been performed. This is part of a program of measurements designed to study the spectrum of baryon resonances in particular, and nonperturbative QCD in general. Purpose: The accurate measurement of several polarization observables provides tight constraints for phenomenological fits, which allow the study of strangeness in nucleon and nuclear systems. Beam-recoil observables for the γ p → K + 0 reaction have not been reported before now. Method: The measurements were carried out using linearly polarized photon beams incident on a liquid hydrogen target, and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71 < W < 2.19 GeV, with an angular range −0.75 < cos θ K < +0.85. Results: The observables extracted for both reactions are beam asymmetry , target asymmetry T , and the beam-recoil double polarization observables O x and O z. Conclusions: Comparison with theoretical fits indicates that, in the regions where no previous data existed, the new data contain significant new information, and strengthen the evidence for the set of resonances used in the latest Bonn-Gatchina fit.
Published: 2016

40. First measurement of the polarization observable E in the View the MathML sourcep→(γ→,π+)n reaction up to 2.25 GeV

Author: Strauch, S., Briscoe, W. J., Döring, M., Klempt, E., Nikonov, V. A., Pasyuk, E., Rönchen, D., Sarantsev, A. V., Strakovsky, I., Workman, R., Adhikari, K. P., Adikaram, D., Anderson, M. D., Pereira, S. Anefalos, Anisovich, A. V., Badui, R. A., Ball, J., Batourine, V., Battaglieri, M., Bedlinskiy, I., Benmouna, N., Biselli, A. S., Brock, J., Brooks, W. K., Burkert, V. D., Cao, T., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., Dashyan, N., d'Angelo, A., de Vita, R., de Sanctis, E., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lenisa, P., Livingston, K., Lu, H. Y., Macgregor, I . J . D., Markov, N., Mckinnon, B., Meekins, D. G., Meyer, C. A., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Munevar, E., Muñoz Camacho, C., Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Peng, P., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, Pascal, Sabatié, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seely, M. L., Senderovich, I, Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stoler, P., Stepanyan, S., Sytnik, V., Taiuti, M., Tian, Ye, Trivedi, A., Tucker, R., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), CLAS Collaboration, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: 6 pages, 3 figures; International audience; First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction $\vec \gamma \vec p \to \pi^+n$, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, J\"ulich, and SAID groups.
Published: 2015

41. Determination of the beam-spin asymmetry of deuteron photodisintegration in the energy region Eγ=1.1–2.3 GeV

Author: Zachariou, N., Ilieva, Y., Berman, B. L., Ivanov, N. Ya., Sargsian, M. M., Avakian, R., Feldman, G., Nadel-Turonski, P., Adhikari, K. P., Adikaram, D., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Badui, R. A., Baltzell, N. A., Battaglieri, M., Baturin, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mattione, P. T., Mckinnon, B., Mineeva, T., Mirazita, M., Mokeeev, V. I., Montgomery, R. A., Moutarde, H., Muñoz Camacho, C., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, Pascal, Sabatié, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stepanyan, S., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Wood, M. H., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: QUANTUM CHROMODYNAMICS, 2-BODY PHOTODISINTEGRATION, LINEARLY POLARIZED PHOTONS, PROTON ELASTIC-SCATTERING, CROSS-SECTION, HARD PHOTODISINTEGRATION, STRING MODEL, CLAS, PHOTOPRODUCTION, DISINTEGRATION, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], NO, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment
Abstract: The beam-spin asymmetry, $\Sigma$, for the reaction $\gamma d\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $\theta_{c.m.}$, between $25^\circ$ and $160^\circ$. These are the first measurements of beam-spin asymmetries at $\theta_{c.m.}=90^\circ$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than $\theta_{c.m.}=90^\circ$. The angular and energy dependence of $\Sigma$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions., Comment: 18 pages
Published: 2015

42. Measurements of $ep \to e'\pi^+n$ at 1.6 < W < 2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS

Author: Park, K., Aznauryan, I.G., Burkert, V.D., Adhikari, K.P., Amaryan, M.J., Pereira, S. Anefalos, Avakian, H., Battaglieri, M., Badui, R., Bedlinskiy, I., Biselli, A.S., Bono, J., Briscoe, W.J., Brooks, W.K., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., Vita, R. De, Sanctis, E. De, Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J.A., Garillon, B., Garçon, M., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Joo, H.S., Goetz, J.T., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guegan, B., Guidal, M., Guo, L., Hakobyan, H., Hanretty, C., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S.M., Hyde, C. E., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jenkins, D., Jiang, H., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Kuhn, S.E., Kuleshov, S.V., Lenisa, P., Livingston, K., Lu, H.Y., MacGregor, I .J .D., Markov, N., Martinez, David, Mckinnon, B., Mokeev, V., Montgomery, R.A., Moutarde, H., Muñoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Paolone, M., Pasyuk, E., Peng, P., Phelps, W., Phillips, J.J., Pisano, S., Pogorelko, O., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A.J.R., Raue, B.A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, Pascal, Sabatié, F., Salgado, C., Schott, D., Schumacher, R.A., Seder, E., Sharabian, Y.G., Simonyan, A., Skorodumina, Iu., Smith, E.S., Smith, G.D., Sparveris, N., Stoler, P., Strakovsky, I.I., Strauch, S., Sytnik, V., Taiuti, M., Tang, W., Taylor, C.E., Tian, Ye, Trivedi, A., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Weinstein, L.B., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: Differential cross sections of the exclusive process $e p \to e^\prime \pi^+ n$ were measured with good precision in the range of the photon virtuality $Q^2 = 1.8 - 4.5$ GeV$^2$, and the invariant mass range of the $\pi^+ n$ final state W = 1.6 - 2.0 GeV using the CEBAF Large Acceptance Spectrometer. Data were collected with nearly complete coverage in the azimuthal and polar angles of the $n\pi^+$ center-of-mass system. More than 37,000 cross section points were measured. The contributions of the isospin $I = {1\over 2}$ resonances $N(1675){5\over 2}^-$, $N(1680){5\over 2}^+$ and $N(1710){1\over 2}^+$ were extracted at different values of $Q^2$ using a single-channel, energy-dependent resonance amplitude analysis. Two different approaches, the unitary isobar model and the fixed-$t$ dispersion relations, were employed in the analysis. We observe significant strength of the $N(1675){5\over 2}^-$ in the $A_{1/2}$ amplitude, which is in strong disagreement with quark models that predict both transverse amplitudes to be strongly suppressed. For the $N(1680){5\over 2}^+$ we observe a slow changeover from the dominance of the $A_{3/2}$ amplitude at the real photon point ($Q^2=0$) to a $Q^2$ where $A_{1/2}$ begins to dominate. The scalar amplitude $S_{1/2}$ drops rapidly with $Q^2$ consistent with quark model prediction. For the $N(1710){1\over 2}^+$ resonance our analysis shows significant strength for the $A_{1/2}$ amplitude at $Q^2 < 2.5$ GeV$^2$., Comment: 24 pages, 22 figures. arXiv admin note: substantial text overlap with arXiv:0709.1946
Published: 2015

43. Measurement of the structure function of the nearly free neutron using spectator tagging in inelastic H2(e,e′ps)X scattering with CLAS

Author: Tkachenko, S., Baillie, N., Kuhn, S. E., Zhang, J., Arrington, J., Bosted, P., B��ltmann, S., Christy, M. E., Dutta, D., Ent, R., Fenker, H., Griffioen, K. A., Ispiryan, M., Kalantarians, N., Keppel, C. E., Melnitchouk, W., Tvaskis, V., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fleming, J. A., Garillon, B., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hyde, C . E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jo, H. S., Keller, D., Khandaker, M., Kim, A., Kim, W., King, P. M., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuleshov, S. V., Lenisa, P., Lewis, S., Livingston, K., Lu, H., MacCormick, M., MacGregor, I. J. D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J . R., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabati��, F., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Simonyan, A., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S., Stepanyan, S. S., Strauch, S., Tang, W., Ungaro, M., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Weinstein, L. B., Wood, M. H., Zana, L., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, nucl-ex
Abstract: Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured the inelastic electron deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model independent extraction of the neutron structure function. A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV/c. For the extraction of the free neutron structure function $F_{2n}$, spectator protons at backward angle and with momenta below 100 MeV/c were selected, ensuring that the scattering took place on a nearly free neutron. The scattered electrons were detected with Jefferson Lab's CLAS spectrometer. The extracted neutron structure function $F_{2n}$ and its ratio to the deuteron structure function $F_{2d}$ are presented in both the resonance and deep inelastic regions. The dependence of the cross section on the spectator proton momentum and angle is investigated, and tests of the spectator mechanism for different kinematics are performed. Our data set can be used to study neutron resonance excitations, test quark hadron duality in the neutron, develop more precise parametrizations of structure functions, as well as investigate binding effects (including possible mechanisms for the nuclear EMC effect) and provide a first glimpse of the asymptotic behavior of d/u as x goes to 1., 28 pages, 22 figures; published in Phys. Rev. C. Revised to include three authors inadvertently left off the original version: D. Dutta, R. Ent, and M. Ispiryan
Published: 2014

44. Strangeness Suppression of qqbar Creation Observed in Exclusive Reaction

Author: Mestayer, M.D., Park, K., P. Adhikari, K., Aghasyan, M., Anefalos Pereira, S., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Doughty, D., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fleming, J.A., Forest, T.A., Garillon, B., Garçon, M., Ghandilyan, Y., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guegan, B., Guidal, M., Hakobyan, H., Hanretty, C., Hattawy, M., Holtrop, M., Hughes, S.M., Hyde, C. E., Ilieva, Y., Ireland, D.G., Jiang, H., Jo, H.S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Koirala, S., Kubarovsky, V., Kuleshov, S.V., Lenisa, P., Levine, W.I., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Mayer, M., Mckinnon, B., Meyer, C.A., Mirazita, M., Mokeev, V., Montgomery, R.A., Moody, C.I., Moutarde, H., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Pappalardo, L.L., Paremuzyan, R., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Protopopescu, D., Puckett, A.J.R., Raue, B.A., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Roy, Pascal, Sabatié, F., Saini, M.S., Schott, D., Schumacher, R.A., Simonyan, A., Sokhan, D., Strauch, S., Sytnik, V., Tang, W., Tian, Ye, Ungaro, M., Vernarsky, B., Vlassov, A.V., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Wei, X., Weinstein, L.B., Wood, M.H., Zachariou, N., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Experiment (hep-ex), Physics - Data Analysis, Statistics and Probability, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Data Analysis, Statistics and Probability (physics.data-an), High Energy Physics - Experiment
Abstract: We measured the ratios of electroproduction cross-sections from a proton target for three exclusive meson-baryon final states: $\Lambda K^+$, $p\pi^0$, and $n\pi^+$, with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization we extract q-qbar creation probabilities for the first time in exclusive two-body production, in which only a single q-qbar pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to non-strange pairs, similar to that seen in high-energy production., Comment: 5pages, 2figures
Published: 2014

45. Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

Author: Moriya, K., Schumacher, R.A., Adhikari, K.P., Adikaram, D., Aghasyan, M., Amaryan, M.J., Anderson, M.D., Anefalos Pereira, S., Avakian, H., Ball, J., Baltzell, N.A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bellis, M., Bennett, R.P., Biselli, A.S., Bono, J., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Carman, D.S., Celentano, A., Chandavar, S., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dey, B., Djalali, C., Doughty, D., Dugger, M., Dupre, R., Egiyan, H., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J.A., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Guler, N., Guo, L., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Joo, K., Keller, D., Khandaker, M., Klein, A., Klein, F.J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S.V., Lewis, S., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Martinez, David, Mayer, M., Mccracken, M., Mckinnon, B., Mestayer, M.D., Meyer, C.A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R.A., Moutarde, H., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Nasseripour, R., Nepali, C.S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Pappalardo, L.L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J.J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Protopopescu, D., Puckett, A.J.R., Raue, B.A., Rimal, D., Ripani, M., Ritchie, B.G., Rosner, G., Rossi, P., Sabatié, F., Saini, M.S., Salgado, C., Schott, D., Seder, E., Seraydaryan, H., Sharabian, Y.G., Smith, G.D., Sober, D.I., Sokhan, D., Stepanyan, S., Stoler, P., Strauch, S., Taiuti, M., Tang, W., Taylor, C.E., Taylor, S., Tian, Y., Tkachenko, S., Ungaro, M., Vernarsky, B., Vineyard, M.F., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Weinstein, L.B., Williams, M., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), CLAS, and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold., 21 pages, 18 figures, to be submitted to PRC, revised to include a missing reference
Published: 2013

46. Transverse polarization of Sigma(+)(1189) in photoproduction on a hydrogen target in CLAS

Author: Nepali, C. S., Amaryan, M., Adhikari, K. P., Aghasyan, M., Pereira, S. Anefalos, Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Collins, P., Contalbrigo, M., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gabrielyan, M. Y., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Torayev, B., Vernarsky, B., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: Experimental results on the $\Sigma^+(1189)$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The $\Sigma^+(1189)$ was reconstructed in the exclusive reaction $\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$ via the $\Sigma^{+} \to p \pi^{0}$ decay mode. The $K^{0}_S$ was reconstructed in the invariant mass of two oppositely charged pions with the $\pi^0$ identified in the missing mass of the detected $p\pi^+\pi^-$ final state. Experimental data were collected in the photon energy range $E_{\gamma}$ = 1.0-3.5 GeV ($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances., Comment: pages 11
Published: 2013

47. Measurement of the Sigma pi photoproduction line shapes near the Lambda(1405)

Author: Moriya, K., Schumacher, R.A., Adhikari, K.P., Adikaram, D., Aghasyan, M., Anderson, M.D., Anefalos Pereira, S., Ball, J., Baltzell, N.A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bellis, M., Biselli, A.S., Bono, J., Boiarinov, S., Briscoe, W.J., Burkert, V.D., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Cole, P.L., Collins, P., Crede, V., D'Angelo, A., Dashyan, N., De Sanctis, E., De Vita, R., Deur, A., Dey, B., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J.A., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F.J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S.V., Kvaltine, N.D., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Markov, N., Mayer, M., Mccracken, M., Mckinnon, B., Mestayer, M.D., Meyer, C.A., Mirazita, M., Mineeva, T., Mokeev, V., Montgomery, R.A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Nasseripour, R., Nepali, C.S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Pappalardo, L.L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J.J., Pisano, S., Pivnyuk, N., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Protopopescu, D., Rimal, D., Ripani, M., Ritchie, B.G., Rosner, G., Rossi, P., Sabatié, F., Saini, M.S., Salgado, C., Schott, D., Seder, E., Seraydaryan, H., Sharabian, Y.G., Smith, E.S., Smith, G.D., Sober, D.I., Stepanyan, S.S., Stepanyan, S., Stoler, P., Strakovsky, I.I., Strauch, S., Taiuti, M., Tang, W., Taylor, S., Taylor, C.E., Tian, Ye, Tkachenko, S., Torayev, B., Ungaro, M., Vernarsky, B., Vlassov, A.V., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Weygand, D.P., Williams, M., Zachariou, N., Zana, L., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: BARYONS, KAON-NUCLEON INTERACTIONS, CHIRAL DYNAMICS, QUARK-MODEL, RESONANCES, STATES, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The reaction gamma + p -> K+ + Sigma + pi was used to determine the invariant mass distributions or "line shapes" of the Sigma+ pi-, Sigma- pi+ and Sigma0 pi0 final states, from threshold at 1328 MeV/c^2 through the mass range of the Lambda(1405) and the Lambda(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W < 2.85 GeV. The three mass distributions differ strongly in the vicinity of the I=0 ��(1405), indicating the presence of substantial I=1 strength in the reaction. Background contributions to the data from the Sigma0(1385) and from K^* Sigma production were studied and shown to have negligible influence. To separate the isospin amplitudes, Breit-Wigner model fits were made that included channel-coupling distortions due to the NKbar threshold. A best fit to all the data was obtained after including a phenomenological I=1, J^P = 1/2^- amplitude with a centroid at 1394\pm20 MeV/c^2 and a second I=1 amplitude at 1413\pm10 MeV/c^2. The centroid of the I=0 Lambda(1405) strength was found at the Sigma pi threshold, with the observed shape determined largely by channel-coupling, leading to an apparent overall peak near 1405 MeV/c^2., Figure got replaced during submission, fixed
Published: 2013

48. Separated Structure Functions for Exclusive $K^+\Lambda$ and $K^+\Sigma^0$ Electroproduction at 5.5 GeV with CLAS

Author: Carman, D.S., Park, K., Raue, B.A., Adhikari, K.P., Adikaram, D., Aghasyan, M., Amaryan, M.J., Anderson, M.D., Anefalos Pereira, S., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N.A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Bono, J., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Celentano, A., Chandavar, S., Charles, G., Cole, P.L., Contalbrigo, M., Cortes, O., Crede, V., d'Angelo, A., Dashyan, N., de Vita, R., de Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J.A., Fradi, A., Gabrielyan, M.Y., Gevorgyan, N., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Gohn, W., Gothe, R.W., Griffioen, K.A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F.J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S.V., Kvaltine, N.D., Lewis, S., Livingston, K., Lu, H.Y., Macgregor, I.J.D., Mao, Y., Martinez, David, Mayer, M., Mckinnon, B., Mestayer, M.D., Meyer, C.A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R.A., Moutarde, H., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Nasseripour, R., Nepali, C.S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Pappalardo, L.L., Paremuzyan, R., Park, S., Pasyuk, E., Phelps, E., Phillips, J.J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A.J.R., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M.S., Salgado, C., Saylor, N.A., Schott, D., Schumacher, R.A., Seder, E., Seraydaryan, H., Sharabian, Y.G., Smith, G.D., Sober, D.I., Sokhan, D., Stepanyan, S.S., Stepanyan, S., Stoler, P., Strakovsky, I.I., Strauch, S., Taiuti, M., Tang, W., Taylor, C.E., Tian, Y., Tkachenko, S., Trivedi, A., Ungaro, M., Vernarsky, B., Voskanyan, H., Voutier, E., Walford, N.K., Weinstein, L.B., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report measurements of the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from an unpolarized proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_U$, $\sigma_{LT}$, $\sigma_{TT}$, and $\sigma_{LT'}$ were extracted from the $\Phi$-dependent differential cross sections acquired with a longitudinally polarized 5.499 GeV electron beam. The data span a broad range of momentum transfers $Q^2$ from 1.4 to 3.9 GeV$^2$, invariant energy $W$ from threshold to 2.6 GeV, and nearly the full center-of-mass angular range of the kaon. The separated structure functions provide an unprecedented data sample, which in conjunction with other meson photo- and electroproduction data, will help to constrain the higher-level analyses being performed to search for missing baryon resonances., Comment: 27 pages, 23 figures
Published: 2013

49. Cross sections for the $\gamma p \to K^{+} \Lambda$ and $\gamma p \to K^{+} \Sigma^{0}$ reactions measured at CLAS

Author: Tang, W., Hicks, K., Keller, D., H. Kim, S., C. Kim, H., Adhikari, K.P., Aghasyan, M., Amaryan, M.J., Anderson, M.D., Anefalos Pereira, S., Baltzell, N.A., Battaglieri, M., Bedlinskiy, I., Biselli, A.S., Bono, J., Boiarinov, S., Briscoe, W.J., Burkert, V.D., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., d'Angelo, A., Dashyan, N., de Vita, R., de Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J.A., Gabrielyan, M.Y., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Joo, K., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F.J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S.V., Livingston, K., Lu, H.Y., Macgregor, I..J .D., Mao, Y., Markov, N., Martinez, David, Mayer, M., Mckinnon, B., Meyer, C.A., Mokeev, V., Moutarde, H., Munevar, E., Muñoz, C., Nadel-Turonski, P., Nepali, C.S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A.I., Pappalardo, L.L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J.J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A.J.R., Raue, B.A., Ripani, M., Rimal, D., Ritchie, B.G., Rosner, G., Rossi, P., Sabatié, F., Saini, M.S., Salgado, C., Schott, D., Schumacher, R.A., Seraydaryan, H., Sharabian, Y.G., Smith, G.D., Sober, D.I., Sokhan, D., Stepanyan, S.S., Stepanyan, S., Stoler, P., Strakovsky, I.I., Strauch, S., Taylor, C.E., Tian, Ye, Tkachenko, S., Torayev, B., Ungaro, M., Vernarsky, B., Vlassov, A.V., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Weinstein, L.B., Weygand, D.P., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The first high-statistics cross sections for the reactions $\gamma p \to K^{*+} \Lambda$ and $\gamma p \to K^{*+} \Sigma^0$ were measured using the CLAS detector at photon energies between threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. Differential cross sections are presented over the full range of the center-of-mass angles, $\theta^{CM}_{K^{*+}}$, and then fitted to Legendre polynomials to extract the total cross section. Results for the $K^{*+}\Lambda$ final state are compared with two different calculations in an isobar and a Regge model, respectively. Theoretical calculations significantly underestimate the $K^{*+} \Lambda$ total cross sections between 2.1 and 2.6 GeV, but are in better agreement with present data at higher photon energies., Comment: 15 pages, 24 figures
Published: 2013

50. Demonstration of a novel technique to measure two-photon exchange effects in elastic $e^\pm p$ scattering

Author: Moteabbed, M., Niroula, M., Raue, B. A., Weinstein, L. B., Adikaram, D., Arrington, J., Brooks, W. K., Lachniet, J., Rimal, Dipak, Ungaro, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lewis, S., Lu, H. Y., MacCormick, M., MacGregor, I . J . D., Martinez, David, Mayer, M., Mckinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moriya, K., Moutarde, H., Munevar, E., Muñoz Camacho, C., Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S., Strauch, S., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Voskanyan, H., Voutier, E., Walford, N. K., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), CLAS, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)
Subjects: FOS: Physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections. We present the results of a new experimental technique for making direct $e^\pm p$ comparisons, which has the potential to make precise measurements over a broad range in $Q^2$ and scattering angles. We use the Jefferson Lab electron beam and the Hall B photon tagger to generate a clean but untagged photon beam. The photon beam impinges on a converter foil to generate a mixed beam of electrons, positrons, and photons. A chicane is used to separate and recombine the electron and positron beams while the photon beam is stopped by a photon blocker. This provides a combined electron and positron beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen target. The large acceptance CLAS detector is used to identify and reconstruct elastic scattering events, determining both the initial lepton energy and the sign of the scattered lepton. The data were collected in two days with a primary electron beam energy of only 3.3 GeV, limiting the data from this run to smaller values of $Q^2$ and scattering angle. Nonetheless, this measurement yields a data sample for $e^\pm p$ with statistics comparable to those of the best previous measurements. We have shown that we can cleanly identify elastic scattering events and correct for the difference in acceptance for electron and positron scattering. The final ratio of positron to electron scattering: $R=1.027\pm0.005\pm0.05$ for $=0.206$ GeV$^2$ and $0.830\leq \epsilon\leq 0.943$.
Published: 2013

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