Author: "Niculescu, G." - Searchworks@Jio Institute Digital Library Search Results

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1,025 results on '"Niculescu, G."'

1. Quasielastic $\overrightarrow{^{3}\mathrm{He}}(\overrightarrow{e},{e'})$ Asymmetry in the Threshold Region

Author: Nycz, M., Armstrong, W., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Benesch, J., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Cates, G., Chen, J-P., Chen, J., Chen, M., Cotton, C., Dalton, M-M., Deltuva, A., Deur, A., Dhital, B., Duran, B., Dusa, S. C., Fernando, I., Fuchey, E., Gamage, B., Gao, H., Gaskell, D., Gautam, T., Gauthier, N., Golak, J., Hansen, J. -O., Hauenstein, F., Henry, W., Higinbotham, D. W., Huber, G., Jantzi, C., Jia, S., Jin, K., Jones, M., Joosten, S., Karki, A., Karki, B., Katugampola, S., Kay, S., Keppel, C., King, E., King, P., Korsch, W., Kumar, V., Li, R., Li, S., Li, W., Mack, D., Malace, S., Markowitz, P., Matter, J., McCaughan, M., Meziani, Z-E., Michaels, R., Mkrtchyan, A., Mkrtchyan, H., Morean, C., Nelyubin, V., Niculescu, G., Niculescu, M., Peng, C., Premathilake, S., Puckett, A., Rathnayake, A., Rehfuss, M., Reimer, P., Riley, G., Roblin, Y., Roche, J., Roy, M., Sauer, P. U., Scopeta, S., Satnik, M., Sawatzky, B., Seeds, S., Širca, S. S., Skibiński, R., Smith, G., Sparveris, N., Szumila-Vance, H., Tadepalli, A., Tadevosyan, V., Tian, Y., Usman, A., Voskanyan, H., Witala, H., Wood, S., Yale, B., Yero, C., Yoon, A., Zhang, J., Zhao, Z., Zheng, X., and Zhou, J.
Subjects: Nuclear Experiment
Abstract: A measurement of the double-spin asymmetry from electron-$^{3}$He scattering in the threshold region of two- and three-body breakup of $^{3}$He was performed at Jefferson Lab, for Q$^{2}$ values of 0.1 and 0.2 (GeV/$c$)$^{2}$. The results of this measurement serve as a stringent test of our understanding of few-body systems. When compared with calculations from plane wave impulse approximation and Faddeev theory, we found that the Faddeev calculations, which use modern nuclear potentials and prescriptions for meson-exchange currents, demonstrate an overall good agreement with data.
Published: 2024

2. Flavor Dependence of Charged Pion Fragmentation Functions

Author: Bhatt, H., Bosted, P., Jia, S., Armstrong, W., Dutta, D., Ent, R., Gaskell, D., Kinney, E., Mkrtchyan, H., Ali, S., Ambrose, R., Androic, D., Gayoso, C. Ayerbe, Bandari, A., Berdnikov, V., Bhetuwal, D., Biswas, D., Boer, M., Brash, E., Camsonne, A., Chen, J. P., Chen, J., Chen, M., Christy, E. M., Covrig, S., Danagoulian, S., Diefenthaler, M., Duran, B., Elaasar, M., Elliot, C., Fenker, H., Fuchey, E., Hansen, J. O., Hauenstein, F., Horn, T., Huber, G. M., Jones, M. K., Kabir, M. L., Karki, A., Karki, B., Kay, S. J. D., Keppel, C., Kumar, V., Lashley-Colthirst, N., Li, W. B., Mack, D., Malace, S., Markowitz, P., McCaughan, M., McClellan, E., Meekins, D., Michaels, R., Mkrtchyan, A., Niculescu, G., Niculescu, I., Pandey, B., Park, S., Pooser, E., Rehfuss, M., Sawatzky, B., Smith, G. R., Szumila-Vance, H., Tadepalli, A. S., Tadevosyan, V., Trotta, R., Voskanyan, H., Wood, S. A., Ye, Z., Yero, C., and Zheng, X.
Subjects: Nuclear Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract: We have measured the flavor dependence of multiplicities for pi^+ and pi^- production in semi-inclusive deep-inelastic scattering (SIDIS) on proton and deuteron targets to explore a possible charge symmetry violation in fragmentation functions. The experiment used an electron beam with energies of 10.2 and 10.6 GeV at Jefferson Lab and the Hall-C spectrometers. The electron kinematics spanned the range 0.3
Published: 2024

3. First Measurement of Deeply Virtual Compton Scattering on the Neutron with Detection of the Active Neutron

Author: CLAS Collaboration, Hobart, A., Niccolai, S., Čuić, M., Kumerički, K., Achenbach, P., Alvarado, J. S., Armstrong, W. R., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bondi, M., Booth, W. A., Bossù, F., Brinkmann, K. -Th., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Burkert, V. D., Cao, T., Capobianco, R., Carman, D. S., Chatagnon, P., Ciullo, G., Cole, P. L., Contalbrigo, M., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Fogler, C., Gates, K., Gavalian, G., Gilfoyle, G. P., Glazier, D., Gothe, R. W., Gotra, Y., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jiang, H., Jo, H. S., Joo, K., Kageya, T., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., MacGregor, I. J. D., Marchand, D., Mascagna, V., Maynes, M., McKinnon, B., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Muñoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Rafael, S. Polcher, Poudel, J., Price, J. W., Prok, Y., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Golubenko, A. A., Salgado, C., Schadmand, S., Schmidt, A., Scott, Marshall B. C., Seroka, E. M., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Tommaso, V., Voskanyan, H., Voutier, E., Watts, D. P, Wei, X., Williams, R., Wood, M. H., Xu, L., Zachariou, N., Zhang, J., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Measuring Deeply Virtual Compton Scattering on the neutron is one of the necessary steps to understand the structure of the nucleon in terms of Generalized Parton Distributions (GPDs). Neutron targets play a complementary role to transversely polarized proton targets in the determination of the GPD $E$. This poorly known and poorly constrained GPD is essential to obtain the contribution of the quarks' angular momentum to the spin of the nucleon. DVCS on the neutron was measured for the first time selecting the exclusive final state by detecting the neutron, using the Jefferson Lab longitudinally polarized electron beam, with energies up to 10.6 GeV, and the CLAS12 detector. The extracted beam-spin asymmetries, combined with DVCS observables measured on the proton, allow a clean quark-flavor separation of the imaginary parts of the GPDs $H$ and $E$., Comment: 7 pages, 6 figures
Published: 2024

4. 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., Avakian, H., Averett, T., Gayoso, C. Ayerbe, 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, L., Chatagnon, P., Chen, C., Chen, J.-P., Chetry, T., Christopher, A., Christy, E., 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., Courtoy, A., Dusa, S. Covrig, Crede, V., 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., de Paula, W., de Téramond, G. F., Deur, A., 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., Alaoui, A. El, Fassi, L. El, 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., Hobbs, T., 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, D. J., 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., Metz, A., Meyer, C. A., Meziani, Z.-E., Mezrag, C., Michaels, R., Miller, G. A., Mineeva, T., Miramontes, A. S., Mirazita, M., Mizutani, K., Mkrtchyan, A., Mkrtchyan, H., 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., Nadolsky, P. M., 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., Phelps, W., 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., West, J. Rittenhouse, 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., Shvedunov, V. I., 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., Yuan, C.-P., Yurov, M., Zachariou, N., Zhang, Z., Zhao, Y., Zhao, Z. W., Zheng, X., Zhou, X., Ziegler, V., and Zihlmann, B.
Published: 2024
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5. A Direct Measurement of Hard Two-Photon Exchange with Electrons and Positrons at CLAS12

Author: Schmidt, A., Briscoe, W. J., Cortes, O., Earnest, L., Grauvogel, G. N., Ratliff, S., Seroka, E. M., Sharp, P., Strakovsky, I. I., Niculescu, G., Diehl, S., Blunden, P. G., Cline, E., Korover, I., Kutz, T., Santiesteban, S. N., Fogler, C., Weinstein, L. B., Marchand, D., Niccolai, S., Voutier, E., D'Angelo, A., Bernauer, J. C., Singh, R., Burkert, V., Hauenstein, F., Higinbotham, D. W., Nguyen, D., Pasyuk, E., Szumila-Vance, H., Wei, X., and Keller, D.
Subjects: Nuclear Experiment
Abstract: One of the most surprising discoveries made at Jefferson Lab has been the discrepancy in the determinations of the proton's form factor ratio $\mu_p G_E^p/G_M^p$ between unpolarized cross section measurements and the polarization transfer technique. Over two decades later, the discrepancy not only persists but has been confirmed at higher momentum transfers now accessible in the 12-GeV era. The leading hypothesis for the cause of this discrepancy, a non-negligible contribution from hard two-photon exchange, has neither been conclusively proven or disproven. This state of uncertainty not only clouds our knowledge of one-dimensional nucleon structure but also poses a major concern for our field's efforts to map out the three-dimensional nuclear structure. A better understanding of multi-photon exchange over a wide phase space is needed. We propose making comprehensive measurements of two-photon exchange over a wide range in momentum transfer and scattering angle using the CLAS12 detector. Specifically, we will measure the ratio of positron-proton to electron-proton elastic scattering cross sections, using the proposed positron beam upgrade for CEBAF. The experiment will use 2.2, 4.4, and 6.6 GeV lepton beams incident on the standard CLAS12 unpolarized hydrogen target. Data will be collected by the CLAS12 detector in its standard configuration, except for a modified trigger to allow the recording of events with beam leptons scattered into the CLAS12 central detector. The sign of the beam charge, as well as the polarity of the CLAS12 solenoid and toroid, will be reversed several times in order to suppress systematics associated with local detector efficiency and time-dependent detector performance. The proposed high-precision determination of two-photon effects will be..., Comment: Experimental Proposal E12+23-008 submitted to Jefferson Lab PAC 51, 34 pages, 18 figures
Published: 2023

6. Beam Spin Asymmetry Measurements of Deeply Virtual $\pi^0$ Production with CLAS12

Author: Kim, A., Diehl, S., Joo, K., Kubarovsky, V., Achenbach, P., Akbar, Z., Alvarado, J. S., Armstrong, Whitney R., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Bianconi, A., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Brinkmann, K. T., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Charles, G., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clary, B., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., DeVita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., ElAlaoui, A., ElFassi, L., Fegan, S., Filippi, A., Fogler, C., Gavalian, G., Gilfoyle, G. P., Gosta, G., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Hung, Yu-Chun, Ilieva, Y., Ireland, D. G., Isupov, E., Jo, H. S., Johnston, R., Joosten, S., Khachatryan, M., Khanal, A., Kim, W., Klimenko, V., Kripko, A., Kuhn, S. E., Lanza, L., Leali, M., Kabir, M. L., Lee, S., Lenisa, P., Li, X., MacGregor, I . J . D., Marchand, D., Mascagna, V., McKinnon, B., Matamoros, D., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., MunozCamacho, C., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Niculescu, G., Osipenko, M., Ouillon, M., 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., Radic, A., Ramasubramanian, N., Reed, Trevor, Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., Yurov, M., Zachariou, N., Zhang, J., Ziegler, V., and Zurek, M.
Subjects: Nuclear Experiment
Abstract: The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive $\pi^0$ production in a wide kinematic region with the photon virtualities $Q^2$ up to 8 GeV$^2$ and the Bjorken scaling variable $x_B$ in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions.The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD $\bar E_T$, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the proton's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities., Comment: arXiv admin note: substantial text overlap with arXiv:2210.14557
Published: 2023

7. 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., Gayoso, C. Ayerbe, 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., Christy, E., 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., Courtoy, A., Dusa, S. Covrig, Crede, V., 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, A., 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., Alaoui, A. El, Fassi, L. El, 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., Blin, A. N. Hiller, Hobart, A., Hobbs, T., 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., Metz, A., 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, Nadolsky, P. M., 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., Phelps, W., 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., West, J. Rittenhouse, 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., Shvedunov, V. I., 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., Yuan, C. -P., Yurov, M., Zachariou, N., Zhang, Z., Zhao, Z. W., Zhao, Y., Zheng, X., Zhou, X., Ziegler, V., Zihlmann, B., de Paula, W, and de Téramond, G. F.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
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., Comment: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figures
Published: 2023

8. First Measurement of the EMC effect in B10 and B11

Author: Karki, A, Biswas, D, Gonzalez, FA, Henry, W, Morean, C, Nadeeshani, A, Sun, A, Abrams, D, Ahmed, Z, Aljawrneh, B, Alsalmi, S, Ambrose, R, Androic, D, Armstrong, W, Arrington, J, Asaturyan, A, Assumin-Gyimah, K, Gayoso, C Ayerbe, Bandari, A, Bane, J, Barrow, J, Basnet, S, Berdnikov, V, Bhatt, H, Bhetuwal, D, Boeglin, WU, Bosted, P, Brash, E, Bukhari, MHS, Chen, H, Chen, JP, Chen, M, Christy, ME, Covrig, S, Craycraft, K, Danagoulian, S, Day, D, Diefenthaler, M, Dlamini, M, Dunne, J, Duran, B, Dutta, D, Elliott, C, Ent, R, Fenker, H, Fomin, N, Fuchey, E, Gaskell, D, Gautam, TN, Hansen, JO, Hauenstein, F, Hernandez, AV, Horn, T, Huber, GM, Jones, MK, Joosten, S, Kabir, ML, Kalantarians, N, Keppel, C, Khanal, A, King, PM, Kinney, E, Ko, HS, Kohl, M, Lashley-Colthirst, N, Li, S, Li, WB, Liyanage, AH, Mack, D, Malace, S, Markowitz, P, Matter, J, Meekins, D, Michaels, R, Mkrtchyan, A, Mkrtchyan, H, Nanda, S, Nguyen, D, Niculescu, G, Niculescu, I, Nuruzzaman, Pandey, B, Park, S, Pooser, E, Puckett, AJR, Rehfuss, M, Reinhold, J, Santiesteban, N, Sawatzky, B, Smith, GR, Szumila-Vance, H, Tadepalli, AS, Tadevosyan, V, Trotta, R, Wood, SA, Yero, C, and Zhang, J
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract: The nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in B10 and B11. Previous measurements of the EMC effect in A≤12 nuclei showed an unexpected nuclear dependence; B10 and B11 were measured to explore the EMC effect in this region in more detail. Results are presented for Be9, B10, B11, and C12 at an incident beam energy of 10.6 GeV. The EMC effect in the boron isotopes was found to be similar to that for Be9 and C12, yielding almost no nuclear dependence in the EMC effect in the range A=4-12. This represents important new data supporting the hypothesis that the EMC effect depends primarily on the local nuclear environment due to the cluster structure of these nuclei.
Published: 2023

9. First measurement of hard exclusive $\pi^- \Delta^{++}$ electroproduction beam-spin asymmetries off the proton

Author: Diehl, S., Trotta, N., Joo, K., Achenbach, P., Akbar, Z., Armstrong, W. R., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Brinkmann, K. -T., Briscoe, W. J., Bulumulla, D., Burkert, V., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Charles, G., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Illari, I., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., 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., Matousek, G., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., Camacho, C. Munoz, Naidoo, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatie, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I., Strauch, S., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Yurov, M., Zachariou, N., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: The polarized cross section ratio $\sigma_{LT'}/\sigma_{0}$ from hard exclusive $\pi^{-} \Delta^{++}$ electroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using a 10.2 GeV / 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. The study, which provides the first observation of this channel in the deep-inelastic regime, focuses on very forward-pion kinematics in the valence regime, and photon virtualities ranging from 1.5 GeV$^{2}$ up to 7 GeV$^{2}$. The reaction provides a novel access to the $d$-quark content of the nucleon and to $p \rightarrow \Delta^{++}$ transition generalized parton distributions. A comparison to existing results for hard exclusive $\pi^{+} n$ and $\pi^{0} p$ electroproduction is provided, which shows a clear impact of the excitation mechanism, encoded in transition generalized parton distributions, on the asymmetry.
Published: 2023
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10. First CLAS12 measurement of DVCS beam-spin asymmetries in the extended valence region

Author: CLAS Collaboration, Christiaens, G., Defurne, M., Sokhan, D., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avakian, H., Gayoso, C. Ayerbe, 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., Bueltmann, S., Bulumulla, D., Burkert, V. D., Cao, T., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holmberg, D. E., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Kabir, M. L., Keller, D., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J . D., Marchand, D., Mascagna, V., Matousek, G., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Molina, E., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., 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., Radic, A., Ramasubramanian, N., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Scott, M. B. C., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Ziegler, V., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: Deeply virtual Compton scattering (DVCS) allows one to probe Generalized Parton Distributions (GPDs) describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarised protons. The results greatly extend the $Q^2$ and Bjorken-$x$ phase space beyond the existing data in the valence region and provide over 2000 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies., Comment: Revised Figure 4 and discussion around the number of effective ANNs after Bayesian reweighting
Published: 2022

11. A multidimensional study of the structure function ratio $\sigma_{LT'}/\sigma_{0}$ from hard exclusive $\pi^+$ electro-production off protons in the GPD regime

Author: Diehl, S., Kim, A., Joo, K., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avagyan, H., Gayoso, C. Ayerbe, Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossu, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Carman, D. S., Celentano, A., Chatagnon, P., 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., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Grifoen, K. A., Guidal, M., Hafdi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Lagerquist, V., Laget, J. -M., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J. D., Marchand, D., Mascagna, V., McKinnon, B., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Molina, Esteban, Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., 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., Reed, Trevor, Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatie, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Spreafco, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: A multidimensional extraction of the structure function ratio $\sigma_{LT'}/\sigma_{0}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime ($t/Q^{2}$ $\ll$ 1) with a wide kinematic range of $x_{B}$ in the valence regime (0.17 $<$ $x_{B}$ $<$ 0.55), and virtualities $Q^{2}$ ranging from 1.5 GeV$^{2}$ up to 6 GeV$^{2}$. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low $Q^{2}$, while the GPD model is more appropriate at high $Q^{2}$., Comment: arXiv admin note: text overlap with arXiv:2007.15677
Published: 2022
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12. First Measurement of $\Lambda$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Author: Chetry, T., Fassi, L. El, Brooks, W. K., Dupré, R., Alaoui, A. El, Hafidi, K., Achenbach, P., 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., De 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., Camacho, C. Munoz, 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., and Zurek, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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
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13. 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., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., 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., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T., Gates, K., Gavalian, G., Gilyan, 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., Ire, 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., Marc, D., Mascagna, V., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Camacho, C. Munoz, 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., and Zurek, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
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: 2022
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14. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author: Paul, S. J., Peck, A., Arratia, M., Gotra, Y., Ziegler, V., De Vita, R., Bossu, F., Defurne, M., Atac, H., Gayoso, C. Ayerbe, 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., Brinkmann, K. Th., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Costantini, G., Angelo, A. D, Dashyan, N., Deur, A., Diehl, S., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Lanza, L., Leali, M., Lenisa, P., Li, X., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Paremuzyan, R., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Sabatie, F., Schadmand, S., Schmidt, A., Shirokov, E. V., Shrestha, U., Simmerling, P., Spreafico, M., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., and Zachariou, N.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract: Several factors can contribute to the difficulty of aligning the sensors of tracking detectors, including a large number of modules, multiple types of detector technologies, and non-linear strip patterns on the sensors. All three of these factors apply to the CLAS12 CVT, which is a hybrid detector consisting of planar silicon sensors with non-parallel strips, and cylindrical micromegas sensors with longitudinal and arc-shaped strips located within a 5~T superconducting solenoid. To align this detector, we used the Kalman Alignment Algorithm, which accounts for correlations between the alignment parameters without requiring the time-consuming inversion of large matrices. This is the first time that this algorithm has been adapted for use with hybrid technologies, non-parallel strips, and curved sensors. We present the results for the first alignment of the CLAS12 CVT using straight tracks from cosmic rays and from a target with the magnetic field turned off. After running this procedure, we achieved alignment at the level of 10~$\mu$m, and the widths of the residual spectra were greatly reduced. These results attest to the flexibility of this algorithm and its applicability to future use in the CLAS12 CVT and other hybrid or curved trackers, such as those proposed for the future Electron-Ion Collider.
Published: 2022
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15. Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei

Author: Paul, S. J., Moran, S., Arratia, M., Alaoui, A. El, Hakobyan, H., Brooks, W., Amaryan, M. J., Armstrong, W. R., Atac, H., 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., Bossu, F., Boiarinov, S., Brinkmann, K. Th., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Celentano, A., 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., Fassi, L. El, Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Guidal, M., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, W., 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., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V. I., Moran, P., Camacho, C. Munoz, Neupane, K., Nguyen, D., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pilleux, N., Pocanic, D., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Rosner, G., Sabatie, F., Salgado, C., 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., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., Ziegler, V., and Zurek, M.
Subjects: Nuclear Experiment
Abstract: We present the first measurement of di-hadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the GiBUU model, which suggests that hadrons form near the nuclear surface and undergo multiple-scattering in nuclei. These results show that angular correlation studies can open a new way to elucidate how hadrons form and interact inside nuclei, Comment: 6 pages, 4 figures
Published: 2022
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16. First Measurement of the EMC Effect in $^{10}$B and $^{11}$B

Author: Karki, A., Biswas, D., Gonzalez, F. A., Henry, W., Morean, C., Nadeeshani, A., Sun, A., Abrams, D., Ahmed, Z., Aljawrneh, B., Alsalmi, S., Ambrose, R., Androic, D., Armstrong, W., Arrington, J., Asaturyan, A., Assumin-Gyimah, K., Gayoso, C. Ayerbe, Bandari, A., Bane, J., Barrow, J., Basnet, S., Berdnikov, V., Bhatt, H., Bhetuwal, D., Boeglin, W. U., Bosted, P., Brash, E., Bukhari, M. H. S., Chen, H., Chen, J. P., Chen, M., Christy, M. E., Covrig, S., Craycraft, K., Danagoulian, S., Day, D., Diefenthaler, M., Dlamini, M., Dunne, J., Duran, B., Dutta, D., Elliott, C., Ent, R., Fenker, H., Fomin, N., Fuchey, E., Gaskell, D., Gautam, T. N., Hansen, J. O., Hauenstein, F., Hernandez, A. V., Horn, T., Huber, G. M., Jones, M. K., Joosten, S., Kabir, M. L., Kalantarians, N., 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., Matter, J., Meekins, D., Michaels, R., Mkrtchyan, A., Mkrtchyan, H., Nanda, S., Nguyen, D., Niculescu, G., Niculescu, I., Nuruzzaman, Pandey, B., Park, S., Pooser, E., Puckett, A. J. R., Rehfuss, M., Reinhold, J., Santiesteban, N., Sawatzky, B., Smith, G. R., Szumila-Vance, H., Tadepalli, A. S., Tadevosyan, V., Trotta, R., Wood, S. A., Yero, C., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: The nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in $^{10}$B and $^{11}$B. Previous measurements of the EMC effect in $A \leq 12$ nuclei showed an unexpected nuclear dependence; $^{10}$B and $^{11}$B were measured to explore the EMC effect in this region in more detail. Results are presented for $^9$Be, $^{10}$B, $^{11}$B, and $^{12}$C at an incident beam energy of 10.6~GeV. The EMC effect in the boron isotopes was found to be similar to that for $^9$Be and $^{12}$C, yielding almost no nuclear dependence in the EMC effect in the range $A=4-12$. This represents important, new data supporting the hypothesis that the EMC effect depends primarily on the local nuclear environment due to the cluster structure of these nuclei., Comment: To appear in PRC
Published: 2022

17. Constraints on the onset of color transparency from quasi-elastic $^{12}$C$(e,e'p)$ up to $Q^2=\,14.2\,$(GeV$/c)^2$

Author: Bhetuwal, D., Matter, J., Szumila-Vance, H., Gayoso, C. Ayerbe, 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., 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., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: Quasi-elastic scattering on $^{12}$C$(e,e'p)$ was measured in Hall C at Jefferson Lab for space-like 4-momentum transfer squared $Q^2$ in the range of 8--14.2\,(GeV/$c$)$^2$ with proton momenta up to 8.3\,GeV/$c$. The experiment was carried out in the upgraded Hall C at Jefferson Lab. It used the existing high momentum spectrometer and the new super high momentum spectrometer to detect the scattered electrons and protons in coincidence. The nuclear transparency was extracted as the ratio of the measured yield to the yield calculated in the plane wave impulse approximation. Additionally, the transparency of the $1s_{1/2}$ and $1p_{3/2}$ shell protons in $^{12}$C was extracted, and the asymmetry of the missing momentum distribution was examined for hints of the quantum chromodynamics prediction of Color Transparency. All of these results were found to be consistent with traditional nuclear physics and inconsistent with the onset of Color Transparency.
Published: 2022
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18. Exclusive $\pi^{-}$ 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., and Zhang, J.
Subjects: Nuclear Experiment
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: 2022
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19. Measurement of R=σL/σT and the separated longitudinal and transverse structure functions in the nucleon-resonance region

Author: Liang, Y, Tvaskis, V, Christy, ME, Ahmidouch, A, Armstrong, CS, Arrington, J, Asaturyan, R, Avery, S, Baker, OK, Beck, DH, Blok, HP, Bochna, CW, Boeglin, W, Bosted, P, Bouwhuis, M, Breuer, H, Brown, DS, Bruell, A, Carlini, RD, Cha, J, Chant, NS, Cochran, A, Cole, L, Danagoulian, S, Day, DB, Dunne, J, Dutta, D, Ent, R, Fenker, HC, Fox, B, Gan, L, Gao, H, Garrow, K, Gaskell, D, Gasparian, A, Geesaman, DF, Gilman, R, Guèye, PLJ, Harvey, M, Holt, RJ, Jiang, X, Jones, M, Keppel, CE, Kinney, E, Lorenzon, W, Lung, A, Mack, DJ, Markowitz, P, Martin, JW, McIlhany, K, McKee, D, Meekins, D, Miller, MA, Milner, RG, Mitchell, JH, Mkrtchyan, H, Mueller, BA, Nathan, A, Niculescu, G, Niculescu, I, O'Neill, TG, Papavassiliou, V, Pate, SF, Piercey, RB, Potterveld, D, Ransome, RD, Reinhold, J, Rollinde, E, Rondon, O, Roos, P, Sarty, AJ, Sawafta, R, Schulte, EC, Segbefia, E, Smith, C, Stepanyan, S, Strauch, S, Tadevosyan, V, Tang, L, Tieulent, R, Uzzle, A, Vulcan, WF, Wood, SA, Xiong, F, Yuan, L, Zeier, M, Zihlmann, B, and Ziskin, V
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract: We report on a detailed study of longitudinal strength in the nucleon resonance region, presenting new results from inclusive electron-proton cross sections measured at Jefferson Lab Hall C in the four-momentum transfer range 0.2
Published: 2022

20. Measurement of the EMC effect in light and heavy nuclei

Author: Arrington, J., Bane, J., Daniel, A., Fomin, N., Gaskell, D., Seely, J., Asaturyan, R., Benmokhtar, F., Boeglin, W., Bosted, P., Bukhari, M. H. S., Christy, M. E., Connell, S., Dalton, M. M., Day, D., Dunne, J., Dutta, D., Fassi, L. El, Ent, R., Fenker, H., Gao, H., Holt, R. J., Horn, T., Hungerford, E., Jones, M. K., Jourdan, J., Kalantarians, N., Keppel, C. E., Kiselev, D., Lung, A. F., Malace, S., Meekins, D. G., Mertens, T., Mkrtchyan, H., Niculescu, G., Niculescu, I., Potterveld, D. H., Perdrisat, C., Punjabi, V., Qian, X., Reimer, P. E., Roche, J., Rodriguez, V. M., Rondon, O., Schulte, E., Slifer, K., Smith, G. R., Solvignon, P., Tadevosyan, V., Tang, L., Testa, G., Trojer, R., Tvaskis, V., Wesselmann, F. R., Wood, S. A., Yuan, L., and Zheng, X.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: Inclusive electron scattering from nuclear targets has been measured to extract the nuclear dependence of the inelastic cross section in Hall C at the Thomas Jefferson National Accelerator facility. Results are presented for 2H, 3He, 4He, 9B, 12C, 63Cu and 197Au at an incident electron beam energy of 5.77 GeV for a range of momentum transfer from Q^2 = 2 to 7 (GeV/c)^2. These data improve the precision of the existing measurements of the EMC effect in the nuclear targets at large x, and allow for more detailed examinations of the A dependence of the EMC effect., Comment: 28 pages, 23 figures, archival paper for Jefferson Lab experiment E03-103
Published: 2021
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21. Measurement of charged-pion production in deep-inelastic scattering off nuclei with the CLAS detector

Author: Moran, S., Dupre, R., Hakobyan, H., Arratia, M., Brooks, W. K., Borquez, A., Alaoui, A. El, Fassi, L. El, Hafidi, K., Mendez, R., Mineeva, T., Paul, S. J., Amaryan, M. J., Angelini, Giovanni, Armstrong, Whitney R., Atac, H., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biondo, L., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., 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., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gothe, R. W., Griffioen, K. A., Guidal, M., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Keller, D., Khanal, A., Khandaker, M., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Meziani, Z. E., 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., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, Trevor, 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., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, Kevin, Wei, X., Weinstein, L. B., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Background: Energetic quarks in nuclear DIS propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimulated gluon bremsstrahlung and intra-nuclear interactions of forming hadrons. More data are required to gain a more complete understanding of these effects. Purpose: To test the theoretical models of parton transport and hadron formation, we compared their predictions for the nuclear and kinematic dependence of pion production in nuclei. Methods: We have measured charged-pion production in semi-inclusive DIS off D, C, Fe, and Pb using the CLAS detector and the CEBAF 5.014 GeV electron beam. We report results on the nuclear-to-deuterium multiplicity ratio for $\pi^{+}$ and $\pi^{-}$ as a function of energy transfer, four-momentum transfer, and pion energy fraction or transverse momentum - the first three-dimensional study of its kind. Results: The $\pi^{+}$ multiplicity ratio is found to depend strongly on the pion fractional energy $z$, and reaches minimum values of $0.67\pm0.03$, $0.43\pm0.02$, and $0.27\pm0.01$ for the C, Fe, and Pb targets, respectively. The $z$ dependences of the multiplicity ratios for $\pi^{+}$ and $\pi^{-}$ are equal within uncertainties for C and Fe targets but show differences at the level of 10$\%$ for the Pb-target data. The results are qualitatively described by the GiBUU transport model, as well as with a model based on hadron absorption, but are in tension with calculations based on nuclear fragmentation functions. Conclusions: These precise results will strongly constrain the kinematic and flavor dependence of nuclear effects in hadron production, probing an unexplored kinematic region. They will help to reveal how the nucleus reacts to a fast quark, thereby shedding light on its color structure, transport properties, and on the mechanisms of the hadronization process., Comment: 22 pages, 5 figures, 12 tables
Published: 2021
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22. 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., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: 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 (EOS). Yet, compared to other elastic scattering processes, there is very little data on $\Lambda$-$N$ scattering. This experiment utilized the CLAS detector to study the $\Lambda p \rightarrow \Lambda p$ elastic scattering cross section in the incident $\Lambda$ momentum range 0.9-2.0 GeV/c. This is the first data on this reaction in several decades. 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., Comment: 6 pages, 5 figures
Published: 2021

23. inclusiveAI: A machine learning representation of the $F_2$ structure function over all charted $Q^2$ and $x$ range

Author: Brown, S., Niculescu, G., and Niculescu, I.
Subjects: High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: Structure function data provide insight into the nucleon quark distribution. They are relatively straightforward to extract from the world's vast, and growing, amount of inclusive lepto-production data. In turn, structure functions can be used to model the physical processes needed for planning and optimizing future experiments. In this paper a machine learning algorithm capable of predicting, using a unique set of parameters, the $F_2$ structure function, for four-momentum transfer $0.055 \leq Q^2 \leq 800.0$ GeV$^2$ and for Bjorken $x$ from $2.8 \times 10^{-5}$ to the pion threshold is presented. The model was trained and reproduces the hydrogen and the deuterium data at the 7~\% level, comparable with the average uncertainty of the experimental data. Extending the model to other nuclei or expanding the kinematic range are straightforward. The model is at least ten times faster than existing structure functions parameterizations, making it an ideal candidate for event generators and systematic studies.
Published: 2021
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24. Deeply virtual Compton scattering using a positron beam in Hall-C at Jefferson Lab

Author: Afanasev, A., Albayrak, I., Ali, S., Amaryan, M., Annand, J. R. M., Asaturyan, A., Bellini, V., Berdnikov, V. V., Boer, M., Brinkmann, K., Briscoe, W. J., Camsonne, A., Caudron, M., Causse, L., Carmignotto, M., Day, D., Defurne, M., Diehl, S., Ent, R., Chatagnon, P., Dupré, R., Dutta, D., Ehrhart, M., Fernando, M. A. I., Forest, T., Guidal, M., Grames, J., Gueye, P., Habet, S., Hamilton, D. J., Hobart, A., Horn, T., Hyde, C., Kalicy, G., Keller, D., Keppel, C., Kerver, M., Kinney, E., Ko, H. -S., Marchand, D., Markowitze, P., Mazouz, M., McCaughan, M., McKinnon, B., Mkrtchyan, A., Mkrtchyan, H., Muhoza, M., Camacho, C. Muñoz, Murphy, J., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Novotny, R., Paremuzyan, R., Pegg, I., Price, K., Rashad, H., Roche, J., Rondon, R., Sawatzky, B., Sergeyeva, V., Širca, S., Somov, A., Strakovsky, I., Tadevosyan, V., Trotta, R., Voskanyan, H., Voutier, E., Wojtsekhowski, B., Wood, S., Zhamkochyan, S., Zhang, J., Zhao, S., and Zorn, C.
Subjects: Nuclear Experiment
Abstract: We propose to use the High Momentum Spectrometer of Hall C combined with the Neutral Particle Spectrometer (NPS) to perform high precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section using a beam of positrons. The combination of measurements with oppositely charged incident beams is the only unambiguous way to disentangle the contribution of the DVCS$^2$ term in the photon electroproduction cross section from its interference with the Bethe-Heitler amplitude. This provides a stronger way to constrain the Generalized Parton Distributions of the nucleon. A wide range of kinematics accessible with an 11 GeV beam off an unpolarized proton target will be covered. The $Q^2-$dependence of each contribution will be measured independently.
Published: 2021
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25. Measurement of the EMC effect in light and heavy nuclei

Author: Arrington, J, Bane, J, Daniel, A, Fomin, N, Gaskell, D, Seely, J, Asaturyan, R, Benmokhtar, F, Boeglin, W, Bosted, P, Bukhari, MHS, Christy, ME, Connell, S, Dalton, MM, Day, D, Dunne, J, Dutta, D, Fassi, L El, Ent, R, Fenker, H, Gao, H, Holt, RJ, Horn, T, Hungerford, E, Jones, MK, Jourdan, J, Kalantarians, N, Keppel, CE, Kiselev, D, Lung, AF, Malace, S, Meekins, DG, Mertens, T, Mkrtchyan, H, Niculescu, G, Niculescu, I, Potterveld, DH, Perdrisat, C, Punjabi, V, Qian, X, Reimer, PE, Roche, J, Rodriguez, VM, Rondon, O, Schulte, E, Slifer, K, Smith, GR, Solvignon, P, Tadevosyan, V, Tang, L, Testa, G, Trojer, R, Tvaskis, V, Wesselmann, FR, Wood, SA, Yuan, L, and Zheng, X
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract: Inclusive electron scattering from nuclear targets has been measured to extract the nuclear dependence of the inelastic cross section (σA) in Hall C at the Thomas Jefferson National Accelerator facility. Results are presented for H2, He3, He4, B9, C12, Cu63, and Au197 at an incident electron beam energy of 5.77 GeV for a range of momentum transfer from Q2 = 2 to 7 (GeV/c)2. These data improve the precision of the existing measurements of the EMC effect in the nuclear targets at large x and allow for more detailed examinations of the A dependence of the EMC effect.
Published: 2021

26. Spectroscopy of $A=9$ hyperlithium by the $(e,e^{\prime}K^{+})$ reaction

Author: Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Meekins, D., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Missing mass spectroscopy with the $(e,e^{\prime}K^{+})$ reaction was performed at Jefferson Laboratory's Hall C for the neutron rich $\Lambda$ hypernucleus $^{9}_{\Lambda}{\rm Li}$. The ground state energy was obtained to be $B_{\Lambda}^{\rm g.s.}=8.84\pm0.17^{\rm stat.}\pm0.15^{\rm sys.}~{\rm MeV}$ by using shell model calculations of a cross section ratio and an energy separation of the spin doublet states ($3/2^{+}_1$ and $5/2^{+}_1$). In addition, peaks that are considered to be states of [$^{8}{\rm Li}(3^{+})\otimes s_{\Lambda}=3/2^{+}_{2}, 1/2^{+}$] and [$^{8}{\rm Li}(1^{+})\otimes s_{\Lambda}=5/2^{+}_{2}, 7/2^{+}$] were observed at $E_{\Lambda}({\rm no.~2})=1.74\pm0.27^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$ and $E_{\Lambda}({\rm no.~3})=3.30\pm0.24^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$, respectively. The $E_{\Lambda}({\rm no.~3})$ is larger than shell model predictions by a few hundred keV, and the difference would indicate that a ${\rm ^{5}He}+t$ structure is more developed for the $3^{+}$ state than those for the $2^{+}$ and $1^{+}$ states in a core nucleus $^{8}{\rm Li}$ as a cluster model calculation suggests., Comment: 5 pages, 3 figures
Published: 2021
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27. Differential cross sections for {\Lambda}(1520) using photoproduction at CLAS

Author: Shrestha, U., Chetry, T., Djalali, C., Hicks, K., Nam, S. i., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., 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., Celentano, A., Chatagnon, P., Ciullo, G., Cole, P. L., Contalbrigo, M., Crede, V., De Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Holtrop, M., Huang, Q., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Turonski, P. Nadel, Neupane, 5 K., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pivnyuk, N., Pogorelko, O., Poudel, J., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment
Abstract: The reaction $\gamma p \rightarrow K^{+} \Lambda(1520)$ using photoproduction data from the CLAS $g12$ experiment at Jefferson Lab is studied. The decay of $\Lambda(1520)$ into two exclusive channels, $\Sigma^{+}\pi^{-}$ and $\Sigma^{-}\pi^{+}$, is studied from the detected $K^{+}$, $\pi^{+}$, and $\pi^{-}$ particles. A good agreement is established for the $\Lambda(1520)$ differential cross sections with the previous CLAS measurements. The differential cross sections as a function of CM angle are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant 4-momentum transfer $t$, which is the natural variable to use for a theoretical model based on a Regge-exchange reaction mechanism. No new $N^*$ resonances decaying into the $K^+\Lambda(1520)$ final state are found., Comment: 16 pages, 12 figures, 2 tables
Published: 2021
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28. 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., and Zhang, J.
Subjects: High Energy Physics - Experiment
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
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29. Multidimensional, high precision measurements of beam single spin asymmetries in semi-inclusive $\pi^{+}$ electroproduction off protons in the valence region

Author: Diehl, S., Kim, A., Angelini, G., Joo, K., Adhikari, S., Amaryan, M., Arratia, M., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Bastami, S., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Brinkmann, K. -T., Briscoe, W. J., Brooks, W., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dugger, M., Dupre, R., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T., 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., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Hyde, C. E., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., Lu, Z., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., 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., Prokudin, A., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Roberts, C. D., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Simmerling, P., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tezgin, K., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, K., Wei, X., Xu, S. -S., Yale, B., Zachariou, N., and Zhang, J.
Subjects: High Energy Physics - Experiment
Abstract: High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6~GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single $\pi^{+}$ SIDIS data over a large kinematic range in Bjorken x, fractional energy and transverse momentum of the hadron as well as photon virtualities $Q^{2}$ ranging from $1-7\,$GeV$^{2}$. In particular, the structure function ratio $F^{\sin\phi}_{LU}/F_{UU}$ has been determined, where $F^{\sin\phi}_{LU}$ is a twist-3 quantity that can reveal novel aspects of emergent hadron mass and quark-gluon correlations within the nucleon. The data's impact on the evolving understanding of the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing transverse momentum dependent parton distribution functions.
Published: 2021
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30. Ruling out color transparency in quasi-elastic $^{12}$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., and Zhang, J.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
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., Comment: 5 pages, 2 figures
Published: 2020
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31. 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, Giovanni, Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., 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., 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., El~Alaoui, A., El~Fassi, L., 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., Jo, H. S., 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., A~Movsisyan, 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., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatié, 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., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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: 2020
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32. Beam spin asymmetry in semi-inclusive electroproduction of a hadron pair

Author: Mirazita, M., Avakian, H., Courtoy, A., Pisano, S., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., 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., Chetry, T., Ciullo, G., Clary, B., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gavalian, G., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., 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., Huang, Q., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., 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., McKinnon, B., Milner, R. G., Mineeva, T., Mokeev, V., Mullen, C., Camacho, C. Munoz, Neupane, K., Niculescu, G., O'Connell, T., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pocanic, D., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Sabatie', F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: A first measurement of the longitudinal beam spin asymmetry ALU in the semi-inclusive electroproduction of pairs of charged pions is reported. ALU is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498 GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the sin(phiR) moments of ALU are extracted for the kinematic variables of interest in the valence quark region. The understanding of di-hadron production is essential for the interpretation of observables in single hadron production in semi-inclusive DIS, and pioneering measurements of single spin asymmetries in di-hadron production open a new avenue in studies of QCD dynamics.
Published: 2020
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33. Backward-angle Exclusive pi0 Production above the Resonance Region

Author: Li, W. B., Huber, G. M., Stevens, J. R., Semenov-Tian-Shansky, K., Szymanowski, L., Pire, B., Amaryan, M., Androic, D., Aniol, K., Armstrong, D., Averett, T., Gayoso, C. Ayerbe, Boeglin, W., Boer, M., Camsonne, A., Chen, J., Dusa, S. Covrig, Deconinck, W., Defurne, M., Delcarro, F., Diefenthaler, M., Diehl, S., Elaasar, M., Fanelli, C., Fegan, S., Fuchey, E., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Blin, A. Hiller, Hurley, A., Hyde, C., Joo, K., Junaid, M., Kalantarians, N., Kay, S., Khachatryan, M., King, P., Kumar, V., Lersch, D., Lorenti, L., Markowitz, P., McCaughan, M., Mkrtchyan, A., Mkrtchyan, H., Niculescu, G., Niculescu, I., Papandreou, Z., Paremuzyan, R., Park, K., Paudyal, D., Roche, J., Rodas, A., Sawatzky, B., Schertz, A., Smith, G., Strakovsky, I., Tadevosyan, V., Usman, A., Voskanyan, H., and Yero, C.
Subjects: Nuclear Experiment
Abstract: The proposed measurement is a dedicated study of the exclusive electroproduction process,1H(e,e'p)pi0, in the backward-angle regime (u-channel process) above the resonance region. The produced pi0 is emitted 180 degrees opposite to the virtual-photon momentum. This study also aims to apply the well-known Rosenbluth separation technique that provides the model-independent differential cross-sections at the never explored u-channel kinematics region. Currently, the "soft-hard transition" in u-channel meson production remains an interesting and unexplored subject. The available theoretical frameworks offer competing interpretations for the observed backward-angle cross section peaks. In a "soft" hadronic Regge exchange description, the backward meson production comes from the interference between nucleon exchange and the meson produced via re-scattering within the nucleon. Whereas in the "hard" GPD-like backward collinear factorization regime, the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes (TDAs), otherwise known as super skewed parton distributions (SuperSPDs). Both TDAs and SPDs are universal non-perturbative objects of nucleon structure accessible only through backward-angle kinematics. The separated cross sections:sigma_T,sigma_L and T/L ratio at Q2=2-6 GeV2, provide a direct test of two predictions from the TDA model. The magnitude and u-dependence of the separated cross sections also provide a direct connection to the re-scattering Regge picture. The extracted interaction radius (from u-dependence) at different Q2 can be used to study the soft-hard transition in the u-channel kinematics. The acquisition of these data will be an important step forward in validating the existence of a backward factorization scheme of the nucleon structure function and establishing its applicable kinematic range.
Published: 2020

34. Extraction of beam-spin asymmetries from the hard exclusive $\pi^{+}$ channel off protons in a wide range of kinematics

Author: Diehl, S., Joo, K., Kim, A., Avakian, H., Kroll, P., Park, K., Riser, D., Semenov-Tian-Shansky, K., Tezgin, K., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boss`u, 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., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., 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., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., 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., McKinnon, B., Meziani, Z. E., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, G., Osipenko, M., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Raue, B. A., Ripani, M., Rizzo, A., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., 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, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.
Published: 2020
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35. An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

Author: Accardi, A., Afanasev, A., Albayrak, I., Ali, S. F., Amaryan, M., Annand, J. R. M., Arrington, J., Asaturyan, A., Atac, H., Avakian, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Barion, L., Battaglieri, M., Bellini, V., Beminiwattha, R., Benmokhtar, F., Berdnikov, V. V., Bernauer, J. C., Bertone, V., Bianconi, A., Biselli, A., Bisio, P., Blunden, P., Boer, M., Bondì, M., Brinkmann, K. -T., Briscoe, W. J., Burkert, V., Cao, T., Camsonne, A., Capobianco, R., Cardman, L., Carmignotto, M., Caudron, M., Causse, L., Celentano, A., Chatagnon, P., Chen, J. -P., Chetry, T., Ciullo, G., Cline, E., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Darmé, L., Day, D., Defurne, M., De Napoli, M., Deur, A., De Vita, R., D'Hose, N., Diehl, S., Diefenthaler, M., Dongwi, B., Dupré, R., Dutrieux, H., Dutta, D., Ehrhart, M., Fassi, L. El, Elouadrhiri, L., Ent, R., Erler, J., Fernando, I. P., Filippi, A., Flay, D., Forest, T., Fuchey, E., Fucini, S., Furletova, Y., Gao, H., Gaskell, D., Gasparian, A., Gautam, T., Girod, F. -X., Gnanvo, K., Grames, J., Grauvoge, G. N., Gueye, P., Guidal, M., Habet, S., Hague, T. J., Hamilton, D. J., Hansen, O., Hasell, D., Hattawy, M., Higinbotham, D. W., Hobart, A., Horn, T., Hyde, C. E., Ibrahim, H., Ilyichev, A., Italiano, A., Joo, K., Joosten, S. J., Khachatryan, V., Kalantarians, N., Kalicy, G., Karky, B., Keller, D., Keppel, C., Kerver, M., Khandaker, M., Kim, A., Kim, J., King, P. M., Kinney, E., Klimenko, V., Ko, H. -S., Kohl, M., Kozhuharov, V., Kriesten, B. T., Krnjaic, G., Kubarovsky, V., Kutz, T., Lanza, L., Leali, M., Lenisa, P., Liyanage, N., Liu, Q., Liuti, S., Mammei, J., Mantry, S., Marchand, D., Markowitz, P., Marsicano, L., Mascagna, V., Mazouz, M., McCaughan, M., McKinnon, B., McNulty, D., Melnitchouk, W., Metz, A., Meziani, Z. -E., Migliorati, S., Mihovilovic, M., Milner, R., Mkrtchyan, A., Mkrtchyan, H., Movsisyan, A., Moutarde, H., Muhoza, M., Camacho, C. Muñoz, Murphy, J., Nadel-Turonski, P., Nardi, E., Nazeer, J., Niccolai, S., Niculescu, G., Novotny, R., Owens, J. F., Paolone, M., Pappalardo, L., Paremuzyan, R., Pasquini, B., Pasyuk, E., Patel, T., Pegg, I., Peng, C., Perera, D., Poelker, M., Price, K., Puckett, A. J. R., Raggi, M., Randazzo, N., Rashad, M. N. H., Rathnayake, M., Raue, B., Reimer, P. E., Rinaldi, M., Rizzo, A., Roblin, Y., Roche, J., Rondon-Aramayo, O., Sabatié, F., Salmè, G., Santopinto, E., Estrada, R. Santos, Sawatzky, B., Schmidt, A., Schweitzer, P., Scopetta, S., Sergeyeva, V., Shabestari, M., Shahinyan, A., Sharabian, Y., Širca, S., Smith, E. S., Sokhan, D., Somov, A., Sparveris, N., Spata, M., Spiesberger, H., Spreafico, M., Stepanyan, S., Stoler, P., Strakovsky, I., Suleiman, R., Suresh, M., Sznajder, P., Szumila-Vance, H., Tadevosyan, V., Tadepalli, A. S., Thomas, A. W., Tiefenback, M., Trotta, R., Ungaro, M., Valente, P., Vanderhaeghen, M., Venturelli, L., Voskanyan, H., Voutier, E., Wojtsekhowski, B., Wood, M. H., Wood, S., Xie, J., Xiong, W., Ye, Z., Yurov, M., Zaunick, H. -G., Zhamkochyan, S., Zhang, J., Zhang, S., Zhao, S., Zhao, Z. W., Zheng, X., Zhou, J., and Zorn, C.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab., Comment: 18 pages, 7 figures This version superseeds the previous version which scientific content was decomposed into several more elaborated articles. All of these articles will be collected in the EPJ A Topical Issue about "Positron beam and physics at Jefferson Lab (e+@Jlab)"
Published: 2020
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36. 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., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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
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37. Probing the core of the strong nuclear interaction

Author: Schmidt, A., Pybus, J. R., Weiss, R., Segarra, E. P., Hrnjic, A., Denniston, A., Hen, O., Piasetzky, E., Weinstein, L. B., Barnea, N., Strikman, M., Larionov, A., Higinbotham, D., Adhikari, S., Amaryan, M., Angelini, G., Asryan, G., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Beck, A., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Biarinov, S., Briscoe, W. J., Brooks, W., Burkert, V. D., Cao, F., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cohen, E., Cole, P. L., 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., Alaoui, A. El, Fassi, L. El, Eugenio, P., Filippi, A., Forest, T. A., Gavalian, G., Gilad, S., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Giuseppe, C., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hauenstein, F., Hayward, T. B., Hicks, K., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D., Ishkanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Korover, I., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., Beck, S. May-Tal, McKinnon, B., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Mustapha, B., Nadel-Turonski, P., Nanda, S., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Patsyuk, M., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatie, F., Salgado, C., Schmookler, B., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, 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., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zheng, X.
Subjects: Nuclear Experiment, Nuclear Theory
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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38. A Conceptual Design Study of a Compact Photon Source (CPS) for Jefferson Lab

Author: Day, D., Degtiarenko, P., Dobbs, S., Ent, R., Hamilton, D. J., Horn, T., Keller, D., Keppel, C., Niculescu, G., Reid, P., Strakovsky, I., Wojtsekhowski, B., and Zhang, J.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document describes the technical design concept of a compact high intensity, multi-GeV photon source. Capable of producing 10^12 equivalent photons per second this novel device will provide unprecedented access to physics processes with very small scattering probabilities such as hard exclusive reactions on the nucleon. When combined with dynamic nuclear polarized targets, its deployment will result in a large gain in polarized experiment figure-of-merit compared to all previous measurements. Compared to a traditional bremsstrahlung photon source the proposed concept presents several advantages, most significantly in providing a full intensity in a small spot at the target and in taking advantage of the narrow angular spread associated with high energy bremsstrahlung compare to the wide angular distribution of the secondary radiation to minimize the operational prompt and activation radiation dose rates., Comment: 16 pages, 20 figures
Published: 2019
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39. Exclusive $\bm{\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4~GeV$\bm{^{2}}$ $\bm{\leq~ Q^{2} \leq~1}$~GeV$\bm{^{2}}$

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., and Zachariou, N.
Subjects: 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: 2019
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40. 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., Bondì, 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., Dupré, 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., Mihovilovič, M., Milner, R., Mkrtchyan, A., Mkrtchyan, H., Movsisyan, A., Camacho, C. Muñoz, Nadel-Turońs, 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., Širca, 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., and Zorn, C.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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., Comment: Letter-of-Intent to Jefferson Lab PAC46
Published: 2019

41. First Measurements of the Double-Polarization Observables $F$, $P$, and $H$ in $\omega$ Photoproduction off Transversely Polarized Protons in the $N^\ast$ 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., Alaoui, A. El, Fassi, L. El, 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, Camacho, C. Munoz, 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., Sabatie, 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., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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: 2018
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42. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author: Paul, S.J., Peck, A., Arratia, M., Gotra, Y., Ziegler, V., De Vita, R., Bossù, F., Defurne, M., Atac, H., Gayoso, C. Ayerbe, 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., Brinkmann, K.-Th., Briscoe, W.J., Brooks, W.K., Bulumulla, D., Burkert, V.D., Capobianco, R., Carman, D.S., Carvajal, J.C., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P.L., Costantini, G., D’Angelo, A., Dashyan, N., Deur, A., Diehl, S., Djalali, C., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G.P., Golubenko, A.A., Gosta, G., Gothe, R.W., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T.B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D.G., Isupov, E.L., Jo, H.S., Johnston, R., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Lanza, L., Leali, M., Lenisa, P., Li, X., MacGregor, I.J.D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Paremuzyan, R., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J.W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Sabatié, F., Schadmand, S., Schmidt, A., Shirokov, E.V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Spreafico, M., Strakovsky, I.I., Strauch, S., Tan, J.A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D.P., Wei, X., Wishart, R., Wood, M.H., and Zachariou, N.
Published: 2023
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43. Measurements of Non-Singlet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for $Q^2 = 4$ $\rm GeV^2$

Author: Albayrak, I., Mamyan, V., Christy, M. E., Ahmidouch, A., Arrington, J., Asaturyan, A., Bodek, A., Bosted, P., Bradford, R., Brash, E., Bruell, A., Butuceanu, C, Coleman, S. J., Commisso, M., Connell, S. H., Dalton, M. M., Danagoulian, S., Daniel, A., Day, D. B., Dhamija, S., Dunne, J., Dutta, D., Ent, R., Gaskell, D., Gasparian, A., Gran, R., Horn, T., Huang, Liting, Huber, G. M., Jayalath, C., Johnson, M., Jones, M. K., Kalantarians, N., Liyanage, A., Keppel, C. E., Kinney, E., Li, Y., Malace, S., Manly, S., Markowitz, P., Maxwell, J., Mbianda, N. N., McFarland, K. S., Meziane, M., Meziani, Z. E., Mills, G. B, Mkrtchyan, H., Mkrtchyan, A., Mulholland, J., Nelson, J., Niculescu, G., Niculescu, I., Pentchev, L., Puckett, A., Punjabi, V., Qattan, I. A., Reimer, P. E., Reinhold, J., Rodriguez, V. M, Rondon-Aramayo, O., Sakuda, M., Sakumoto, W. K., Segbefia, E., Seva, T., Sick, I., Slifer, K., Smith, G. R, Steinman, J., Solvignon, P., Tadevosyan, V., Tajima, S., Tvaskis, V., Smith, G. R., Vulcan, W. F., Walton, T., Wesselmann, F. R, Wood, S. A., and Ye, Zhihong
Subjects: Nuclear Experiment
Abstract: We present extractions of the nucleon non-singlet moments utilizing new precision data on the deuteron $F_2$ structure function at large Bjorken-$x$ determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world data sets on the proton and deuteron at lower $x$ measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the $x$ range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high $x$ data. Moreover, recent exciting developments in Lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach which first calculates the quark distributions directly before determining moments.
Published: 2018
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44. 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., and Zhao, Z. W.
Subjects: Nuclear Experiment
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: 2018
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45. Beam-Target Helicity Asymmetry $E$ in $K^{0}\Lambda$ and $K^{0}\Sigma^0$ Photoproduction on the Neutron

Author: CLAS Collaboration, 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., Contalbrigo, M., Crede, V., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, 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, Camacho, C. Munoz, 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., and Zonta, I.
Subjects: Nuclear Experiment
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
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46. Separated Kaon Electroproduction Cross Section and the Kaon Form Factor from 6 GeV JLab Data

Author: Carmignotto, M., Ali, S., Aniol, K., Arrington, J., Barrett, B., Beise, E. J., Blok, H. P., Boeglin, W., Brash, E. J., Breuer, H., Chang, C. C., Christy, M. E., Dittmann, A., Ent, R., Fenker, H., Gaskell, D., Gibson, E., Holt, R. J., Horn, T., Huber, G. M., Jin, S., Jones, M. K., Keppel, C. E., Kim, W., King, P. M., Kovaltchouk, V., Liu, J., Lolos, G. J., Mack, D. J., Margaziotis, D. J., Markowitz, P., Matsumura, A., Meekins, D., Miyoshi, T., Mkrtchyan, H., Niculescu, G., Niculescu, I., Okayasu, Y., Pegg, I., Pentchev, L., Perdrisat, C., Potterveld, D., Punjabi, V., Reimer, P. E., Reinhold, J., Roche, J., Sarty, A., Smith, G. R., Tadevosyan, V., Tang, L. G., Trotta, R., Tvaskis, V., Vargas, A., Vidakovic, S., Volmer, J., Vulcan, W., Warren, G., Wood, S. A., Xu, C., and Zheng, X.
Subjects: Nuclear Experiment
Abstract: The $^{1}H$($e,e^\prime K^+$)$\Lambda$ reaction was studied as a function of the Mandelstam variable $-t$ using data from the E01-004 (FPI-2) and E93-018 experiments that were carried out in Hall C at the 6 GeV Jefferson Lab. The cross section was fully separated into longitudinal and transverse components, and two interference terms at four-momentum transfers $Q^2$ of 1.00, 1.36 and 2.07 GeV$^2$. The kaon form factor was extracted from the longitudinal cross section using the Regge model by Vanderhaeghen, Guidal, and Laget. The results establish the method, previously used successfully for pion analyses, for extracting the kaon form factor. Data from 12 GeV Jefferson Lab experiments are expected to have sufficient precision to distinguish between theoretical predictions, for example recent perturbative QCD calculations with modern parton distribution amplitudes. The leading-twist behavior for light mesons is predicted to set in for values of $Q^2$ between 5-10 GeV$^2$, which makes data in the few GeV regime particularly interesting. The $Q^2$ dependence at fixed $x$ and $-t$ of the longitudinal cross section we extracted seems consistent with the QCD factorization prediction within the experimental uncertainty.
Published: 2018
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47. Conceptual Design Report A Compact Photon Source

Author: Wojtsekhowski, B. and Niculescu, G.
Subjects: Physics - Accelerator Physics, High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract: We propose to build a shielded magnet that will act as an untagged bremsstrahlung photon source suitable for deployment in Hall A/C at Jefferson Lab. The goal of the project is a compact source which provides a narrow 1-mm diameter photon beam at the target with the intensity adequate to the polarized target operation. The proposed solution is based on the absorption of the electron beam in the magnet. The compactness is achieved by means of a shallow channel which leads to an electromagnetic shower in the Cu-W body of the channel and surrounding material after a 1-2~mm deflection of the beam electrons by a horizontal magnetic field. This source will allow us to achieve ten times the luminosity of the mixed electron--photon beam configuration while keeping the heat load on the (polarized) target as well as the radiation level in the experimental hall at acceptable levels. The concept for this device was developed for the experimental proposal PR12-15-003 but, if built, it would become a general--purpose source that would be usable for a variety of photon--induced reactions of interest in the 12-GeV era., Comment: 26 pages, 34 figures
Published: 2017

48. Double $K_S^0$ Photoproduction off the Proton at CLAS

Author: Chandavar, S., Goetz, J. T., Hicks, K., Keller, D., Kunkel, M. C., Paolone, M., Weygand, D. P., Adhikari, K. P., Adhikari, S., Akbar, Z., Ball, J., Balossino, I., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., 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., Fradi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., 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., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Johnston, S., Joo, K., Joosten, S., Kabir, M. L., 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., Markov, N., McCracken, M. E., McKinnon, B., Meyer, C. A., Mineeva, T., Mokeev, V., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Sokhan, D., Smith, G. D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Ungaro, M., Voutier, E., Wei, X., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: The $f_0$(1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the $f_0$(1500) via decay into the $K_S^0 K_S^0$ channel using the CLAS detector. The reaction $\gamma p$ -> $f_0 p$ -> $K_S^0 K_S^0 p$, where J = 0, 2, was measured with photon energies from 2.7 to 5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured 4-momentum transfer to the proton target is restricted to be less than 1.0 GeV2. By comparing data with simulations, it can be concluded that the peak at 1500 MeV is produced primarily at low t, which is consistent with a t-channel production mechanism., Comment: 12 pages, 12 figures
Published: 2017
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49. Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q2=4 GeV2

Author: Albayrak, I, Mamyan, V, Christy, ME, Ahmidouch, A, Arrington, J, Asaturyan, A, Bodek, A, Bosted, P, Bradford, R, Brash, E, Bruell, A, Butuceanu, C, Coleman, SJ, Commisso, M, Connell, SH, Dalton, MM, Danagoulian, S, Daniel, A, Day, DB, Dhamija, S, Dunne, J, Dutta, D, Ent, R, Gaskell, D, Gasparian, A, Gran, R, Horn, T, Huang, Liting, Huber, GM, Jayalath, C, Johnson, M, Jones, MK, Kalantarians, N, Liyanage, A, Keppel, CE, Kinney, E, Li, Y, Malace, S, Manly, S, Markowitz, P, Maxwell, J, Mbianda, NN, McFarland, KS, Meziane, M, Meziani, ZE, Mills, GB, Mkrtchyan, H, Mkrtchyan, A, Mulholland, J, Nelson, J, Niculescu, G, Niculescu, I, Pentchev, L, Puckett, A, Punjabi, V, Qattan, IA, Reimer, PE, Reinhold, J, Rodriguez, VM, Rondon-Aramayo, O, Sakuda, M, Sakumoto, WK, Segbefia, E, Seva, T, Sick, I, Slifer, K, Smith, GR, Steinman, J, Solvignon, P, Tadevosyan, V, Tajima, S, Tvaskis, V, Vulcan, WF, Walton, T, Wesselmann, FR, Wood, SA, and Ye, Zhihong
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, E06-009 Collaboration, nucl-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.
Published: 2019

50. 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., Pereira, S. Anefalos, 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., Alaoui, A. El, Fassi, L. El, 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., Camacho, C. Munoz, 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., Sabatie, 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., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
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: 2017
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