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Start Over Author "Paolone, M" Publisher american physical society
53 results on '"Paolone, M"'

1. Polarized structure function σLT′ from π0p electroproduction data in the resonance region at 0.4GeV2<Q2<1.0GeV2

Author

Isupov, E. L., Burkert, V. D., Golubenko, A. A., Joo, K., Markov, N. S., Mokeev, V. I., Smith, L. C., Armstrong, W. R., Atac, H., Avakian, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossù, F., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Capobianco, R. A., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Clary, B. A., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Gilfoyle, G. P., Glazier, D.I., 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., Illari, I., Ireland, D.G., Jenkins, D., Jo, H. S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Klimenko, V., 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., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Munoz Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., O'Connell, T., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Ritman, J., Rowley, J., Sabatié, 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., Watts, D., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Ziegler, V.

Subjects
High Energy Physics::Experiment, ddc:530, Nuclear Experiment
Abstract

The first results on the σLT′ structure function in exclusive π0p electroproduction at invariant masses of the final state of 1.5GeV

Published
2022
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2. Polarized structure function σLT′ from π0p electroproduction data in the resonance region at 0.4 GeV2 < Q2 < 1.0 GeV2

Author

Isupov, El, Burkert, Vd, Golubenko, Aa, Joo, K, Markov, Ns, Mokeev, Vi, Smith, Lc, Armstrong, Wr, Atac, H, Avakian, H, Baltzell, Na, Barion, L, Battaglieri, M, Bedlinskiy, I, Benmokhtar, F, Bianconi, A, Biondo, L, Biselli, As, Bondi, M, Boss??, F, Briscoe, Wj, Brooks, Wk, Bulumulla, D, Capobianco, Ra, Carman, Ds, Carvajal, Jc, Chatagnon, P, Chesnokov, V, Ciullo, G, Cole, Pl, Clary, Ba, Contalbrigo, M, Costantini, G, D'Angelo, A, Dashyan, N, De Vita, R, Defurne, M, Deur, A, Diehl, S, Djalali, C, Dupre, R, Egiyan, H, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Eugenio, P, Fegan, S, Filippi, A, Gavalian, G, Gilfoyle, Gp, Glazier, Di, Gothe, Rw, Griffioen, Ka, Guidal, M, Guo, L, Hafidi, K, Hakobyan, H, Hattawy, M, Hayward, Tb, Heddle, D, Hicks, K, Hobart, A, Holtrop, M, Illari, I, Ireland, Dg, Jenkins, D, H. S., J, Keller, D, Khanal, A, Khandaker, M, Kim, A, Kim, W, Klein, Fj, Klimenko, V, Kripko, A, Kubarovsky, V, Lagerquist, V, Lanza, L, Leali, M, Lenisa, P, Livingston, K, Macgregor, Ijd, Marchand, D, Marsicano, L, Mascagna, V, Mckinnon, B, Meziani, Ze, Migliorati, S, Mineeva, T, Mirazita, M, Munoz Camacho, C, Nadel-Turonski, P, Neupane, K, Niccolai, S, O'Connell, T, Osipenko, M, Pandey, P, Paolone, M, Pappalardo, Ll, Paremuzyan, R, Pasyuk, E, Paul, Sj, Phelps, W, Pilleux, N, Pogorelko, O, Poudel, J, Price, Jw, Prok, Y, Raue, Ba, Reed, T, Ripani, M, Ritman, J, Rowley, J, Sabati??, F, Salgado, C, Schmidt, A, Schumacher, Ra, Sharabian, Yg, Shirokov, Ev, Shrestha, U, Simmerling, P, Sokhan, D, Sparveris, N, Stepanyan, S, Strakovsky, Ii, Strauch, S, Tan, Ja, Tyson, R, Ungaro, M, Vallarino, S, Venturelli, L, Voskanyan, H, Voutier, E, Watts, D, Wei, K, Wei, X, Wood, Mh, Yale, B, Zachariou, N, Zhang, J, and Ziegler, V

Subjects
Settore FIS/04
Published
2022

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

Author

Celentano, A., Battaglieri, M., De Vita, R., Marsicano, L., Mathieu, V., Pilloni, A., Szczepaniak, A., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Barion, L., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., Cruz-Torres, R., D'Angelo, A., Dashyan, N., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Gevorgyan, N., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., Lucherini, V., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., McCracken, M. E., McKinnon, B., Meziani, Z.-E., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R. A., Shrestha, U., Sokan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS

Subjects
Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Hadronic Physics and QCD, Socio-culturale, FOS: Physical sciences, Regge, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], beam: energy, High Energy Physics - Experiment, Nuclear Theory (nucl-th), differential cross section: measured, High Energy Physics - Experiment (hep-ex), PE2_2, PE2_1, CLAS, mass spectrum: (pi0 eta), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], angular distribution, photon p: exclusive reaction, Nuclear Experiment (nucl-ex), Nuclear Experiment, PE2_3, Nucleons, Mesons, Settore FIS/04, photon p: inelastic scattering, partial wave analysis, photon: energy, Photoproduction, meson: photoproduction, experimental results
Abstract

We present the first measurement of the exclusive reaction $\gamma p \rightarrow a_2(1320)^0 \, p$ in the photon energy range $3.5$-$5.5$ GeV and four-momentum transfer squared $0.2, Comment: Version accepted for publication in PRC, "Rapid Communications" section

Published
2020
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4. Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2≤Q2≤1 GeV2 EXCLUSIVE π0p ELECTROPRODUCTION off ⋯ N. MARKOV et al

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., Ayerbe Gayoso, C., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Biselli, A. S., Bossu, 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., H. S., Jo, 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., Rosner, G., Rowley, J., Sabatie, 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.

Published
2020

5. Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4GeV2 ≤ Q2 ≤ 1GeV2

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., Ayerbe Gayoso, C., 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., Rosner, G., 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
QC
Abstract

The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 system of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 center-of-mass system and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+εσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* 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 Nπ and π+π−p channels.

Published
2020

6. Ξ* photoproduction from threshold to W=3.3 GeV

Author

Goetz, J.T., Hicks, K., Kunkel, M.C., Price, J.W., Weygand, D.P., Adhikari, S., Anefalos Pereira, S., Battaglieri, M., Bedlinskiy, I., Biselli, A.S., Boiarinov, S., Bookwalter, C., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Cao, F., Carman, D.S., Celentano, A., Chandavar, S., Chatagnon, P., Chetry, T., Ciullo, G., 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., Elouadrhiri, L., Eugenio, P., Fedotov, G., Filippi, A., Gevorgyan, N., Ghandilyan, Y., Girod, F.X., Glazier, D.I., Golovatch, E., Gothe, R.W., Griffioen, K.A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Joosten, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, F.J., Kubarovsky, V., Lanza, L., Livingston, K., MacGregor, I.J.D., McKinnon, B., Meyer, C.A., Mirazita, M., Mokeev, V., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Prok, Y., Protopopescu, D., Raue, B.A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Saini, M.S., Salgado, C., Schott, D., Schumacher, R.A., Sharabian, Y.G., Skorodumina, Iu., Sober, D.I., Sokhan, D., Sparveris, N., Strakovsky, I.I., Strauch, S., Taiuti, M., Tan, J.A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M.H., Zachariou, N., Zhang, J., and Zhao, Z.W.

Subjects
Nuclear and High Energy Physics, Nuclear Theory, Socio-culturale, High Energy Physics::Experiment, Nuclear Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract

The doubly strange Ξ baryons provide an effective way to study a puzzle called the missing-baryons problem where both quark models and lattice gauge theory predict more baryon excited states than are seen experimentally. However, few of these excited states have been observed with any certainty. Here, high-mass Ξ∗ states have been searched for in photoproduction with the detector of the CLAS Collaboration, and upper limits for the total cross sections have been established from threshold to W=3.3 GeV. In addition, the total cross sections of the ground-state Ξ−(1320) and first excited state Ξ−(1530) are presented, extending significantly the center-of-mass energy range of previous data.

Published
2018

7. Beam-target helicity asymmetry E in K0Λ and K0Σ0 photoproduction on the neutron

Author

Ho, D. H., Schumacher, R. A., D'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Klein, F. J., Klempt, E., Lowry, M. M., Lu, H., Nikonov, V. A., Peng, P., Sandorfi, A. M., Sarantsev, A. V., Strakovsky, I. I., Walford, N. K., Wei, X., Workman, R. L., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Ball, J., Barion, L., Bashkanov, M., Bass, C. D., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Boiarinov, S., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P., Collins, P., Contalbrigo, M., Crede, V., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Laine, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I.J.D., Marchand, D., Markov, N., Mayer, M., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R.A., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Rehfuss, M., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Weinstein, L. B., Whisnant, C. S., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear and High Energy Physics, Nuclear Theory, Socio-culturale, Nuclear Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract

We report the first measurements of the E beam-target helicity asymmetry for the →γ→n→K0Λ and K0Σ0 channels in the energy range 1.70≤W≤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 is 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 photocoupling transition amplitudes in pseudoscalar meson photoproduction.

Published
2018

8. Center of mass motion of short-range correlated nucleon pairs studied via the A(e,e'pp) reaction

Author

Cohen, E O, Hen, O, Piasetzky, E, Weinstein, L B, Duer, M, Schmidt, A, Korover, I, Hakobyan, H, Adhikari, S, Akbar, Z, Amaryan, M J, Avakian, H, Ball, J, Barion, L, Battaglieri, M, Beck, A, Bedlinskiy, I, Biselli, A S, Boiarinov, S, Briscoe, W, Burkert, V D, Cao, F, Carman, D S, Celentano, A, Charles, G, Chatagnon, Pierre, Chetry, T, Ciullo, G, Clary, Brandon A, Contalbrigo, M, Crede, V, Cruz Torres, R, D'Angelo, A, Dashyan, N, De Vita, R, De Sanctis, E, Defurne, M, Deur, A, Diehl, S, Djalali, C, Dupre, R, Egiyan, H, Ehrhart, Mathieu, El Alaoui, A, Fassi, L El, Eugenio, P, Fedotov, G, Fersch, R, Filippi, A, Ghandilyan, Y, Giovanetti, K L, Girod, F X, Golovatch, E, Gothe, R W, Griffioen, K A, Hafidi, K, Harrison, N, Hauenstein, F, Heddle, D, Hicks, K, Holtrop, M, Ireland, D.G., Ishkhanov, B S, Isupov, E L, Jenkins, D, Jo, H S, Johnston, S, Kabir, M L, Keller, D, Khachatryan, G, Khachatryan, M, Khandaker, M, Kim, A, Kim, W, Klein, A, Klein, F J, Kubarovsky, V, Kuhn, S E, Lanza, L, Lenisa, P, Livingston, K., MacGregor, I.J.D., Marchand, D, McKinnon, B., Mey-Tal Beck, S, Meyer, C A, Mirazita, M, Mokeev, V, Montgomery, R.A., Movsisyan, A, Munoz Camacho, C, Mustapha, B, Nadel-Turonski, P, Niccolai, S, Niculescu, G, Osipenko, M, Ostrovidov, A I, Paolone, M, Paremuzyan, R, Pasyuk, E, Pogorelko, O, Price, J W, Prok, Y, Protopopescu, D., Ripani, M, Riser, D, Rizzo, A, Rosner, G., Rossi, P, Sabatié, F, Schmookler, B A, Schumacher, R A, Sharabian, Y G, Sokhan, D., Sparveris, N, Stepanyan, S, Strauch, S, Taiuti, M, Tan, J A, Ungaro, M, Voskanyan, H, Voutier, E, Wang, R, Watts, D P, Wei, X, Wood, M H, Zachariou, N, Zhang, J, Zheng, X, and Zhao, Z W

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.

Published
2018

9. Measurements of the γvp→p′π+π- cross section with the CLAS detector for 0.4 GeV2<Q2<1.0 GeV2 and 1.3 GeV<W<1.825 GeV

Author

Fedotov, Gv, Skorodumina, Ia, Burkert, Vd, Gothe, Rw, Hicks, K, Mokeev, Vi, Adhikari, S, Armstrong, Wr, Avakian, H, Ball, J, Balossino, I, Barion, L, Bashkanov, M, Battaglieri, M, Batourine, V, Bedlinskiy, I, Biselli, As, Boiarinov, S, Briscoe, Wj, Brooks, Wk, Carman, Ds, Celentano, A, Charles, G, Chetry, T, Ciullo, G, Clary, Ba, Cole, Pl, Contalbrigo, M, Cortes, O, D'Angelo, A, Dashyan, N, De Vita, R, De Sanctis, E, Defurne, M, Deur, A, Djalali, C, Dupre, R, Egiyan, H, Fassi, Le, Eugenio, P, Fersch, R, Gavalian, G, Ghandilyan, Y, Gilfoyle, Gp, Girod, Fx, Golovatch, E, Griffioen, Ka, Guo, L, Hafidi, K, Hakobyan, H, Hanretty, C, Harrison, N, Hattawy, M, Heddle, D, Holtrop, M, Ilieva, Y, Ireland, Dg, Ishkhanov, Bs, Isupov, El, Jenkins, D, H. S., J, Johnston, S, Joosten, S, Kabir, Ml, Keller, D, Khachatryan, G, Khachatryan, M, Khandaker, M, Kim, A, Kim, W, Klein, A, Klein, Fj, Kubarovsky, V, Kuleshov, Sv, Lanza, L, Lenisa, P, Livingston, K, Macgregor, Ijd, Markov, N, Mckinnon, B, Mineeva, T, Montgomery, Ra, Camacho, Cm, Nadel-Turonski, P, Niccolai, S, Niculescu, G, Osipenko, M, Paolone, M, Paremuzyan, R, Park, K, Pasyuk, E, Pogorelko, O, Price, Jw, Procureur, S, Prok, Y, Protopopescu, D, Ripani, M, Riser, D, Ritchie, Bg, Rizzo, A, Sabatié, F, Salgado, C, Schumacher, Ra, Sharabian, Yg, Smith, Gd, Sober, Di, Sokhan, D, Sparveris, N, Strakovsky, Ii, Strauch, S, Taiuti, M, Tan, Ja, Tyler, N, Ungaro, M, Voskanyan, H, Voutier, E, Wei, X, Wood, Mh, Zachariou, N, Zhang, J, and Zhao, Zw

Subjects
Nuclear and High Energy Physics, Settore FIS/04 - Fisica Nucleare e Subnucleare
Published
2018

10. Measurements of the γvp→p′π+π− cross section with the CLAS detector for 0.4GeV2 < Q2 < 1.0GeV2 and 1.3GeV < W < 1.825GeV

Author

Fedotov, G. V., Skorodumina, Iu. A., Burkert, V. D., Gothe, R. W., Hicks, K., Mokeev, V. I., Adhikari, S., Armstrong, Whitney R., Avakian, H., Ball, J., Balossino, I., Barion, L., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clary, Brandon A., Cole, P. L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fersch, R., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Golovatch, E., Griffioen, K. A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joosten, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Mineeva, T., Montgomery, R. A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

New results on the single-differential and fully integrated cross sections for the process γvp → p\ud π+π− are\ud presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements\ud were carried out in the kinematic region of the reaction invariant mass W from 1.3 to 1.825 GeV and the photon\ud virtuality Q2 from 0.4 to 1.0 GeV2\ud . The cross sections were obtained in narrow Q2 bins (0.05 GeV2\ud ) with the\ud smallest statistical uncertainties achieved in double-pion electroproduction experiments to date. The results were\ud found to be in agreement with previously available data where they overlap. A preliminary interpretation of\ud the extracted cross sections, which was based on a phenomenological meson-baryon reaction model, revealed\ud substantial relative contributions from nucleon resonances. The data offer promising prospects to improve\ud knowledge on the Q2 evolution of the electrocouplings of most resonances with masses up to ∼1.8 GeV.

Published
2018

11. Exclusive photoproduction of π0 up to large values of Mandelstam variables s, t, and u with CLAS

Author

Kunkel, M. C., Amaryan, M. J., Strakovsky, I. I., Ritman, J., Goldstein, G. R., Adhikari, K. P., Adhikari, S., Avakian, H., Ball, J., Balossino, I., Barion, L., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bultmann, S., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Degtyarenko, P. V., Defurne, M., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fradi, A., Gavalian, G., Ghandilyan, Y., Ghosh, S., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F., Kubarovsky, V., Kuhn, S. E., Laget, J. M., Lanza, L., Lenisa, P., Lersch, D., Livingston, K., Macgregor, I. J. D., Markov, N., Mbianda Njencheu, G., Mckinnon, B., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Park, K., Pasyuk, E., Payette, D., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, A., Sabatie, F., Salgado, C., Schadmand, S., Schumacher, R. A., Sharabian, Y. G., Skorodumina, I., Stepanyan, S., Sokhan, D., Sober, D. I., Sparveris, N., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Watts, D. P., Weinstein, L., Wei, X., Weygand, D. P., Zachariou, N., Zhang, J., and Zhao, Z. W.

Published
2018

12. Measurement of the helicity asymmetry E in ω → π+π−π0 photoproduction

Author

Akbar, Z., Roy, P., Park, S., Crede, V., Anisovich, A. V., Denisenko, I., Klempt, E., Nikonov, V. A., Sarantsev, A. V., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Anefalos Pereira, S., Avakian, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Burkert, V. D., Cao, F. T., Carlin, C., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fradi, A., Garcon, M., Gevorgyan, N., 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., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Ireland, D.G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Joosten, S., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Livingston, K., MacGregor, I.J.D., Markov, N., McKinnon, B., Meekins, D. G., Mineeva, T., Mokeev, V., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., and Zhao, Z. W.

Subjects
Nuclear Experiment
Abstract

The double-polarization observable E was studied for the reaction γp → pω using the CEBAF Large\ud Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the\ud longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay\ud mode of the meson, ω → π+π−π0, using a circularly polarized tagged-photon beam with energies ranging\ud from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found\ud dominant contributions from the 3/2+ partial wave near threshold, which is identified with the subthreshold\ud N(1720) 3/2+ nucleon resonance. To describe the entire data set, which consisted of ω differential cross sections\ud and a large variety of polarization observables, further contributions from other nucleon resonances were found\ud to be necessary. With respect to nonresonant mechanisms, π exchange in the t channel was found to remain small\ud across the analyzed energy range, while Pomeron t-channel exchange gradually grew from the reaction threshold\ud to dominate all other contributions above W ≈ 2 GeV.

Published
2017

13. Determination of the proton spin structure functions for 0.05 < Q2 < 5GeV2 using CLAS

Author

Fersch, R. G., Guler, N., Bosted, P., Deur, A., Griffioen, K., Keith, C., Kuhn, S. E., Minehart, R., Prok, Y., Adhikari, K. P., Adhikari, S., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Asryan, G., Avakian, H., Ball, J., Balossino, I., Baltzell, N. A., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Bültmann, S., Burkert, V. D., Thanh Cao, Frank, Carman, D. S., Careccia, S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Forest, T. A., Garçon, M., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Joo, K., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lagerquist, V. G., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pierce, J., Pisano, S., Pogorelko, O., Price, J. W., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., and Zhang, J.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

We present the results of our final analysis of the full data set of \ud g\ud p\ud 1\ud (\ud Q\ud 2\ud )\ud , the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000–2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets (\ud 15\ud NH\ud 3\ud dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries \ud A\ud p\ud 1\ud and \ud A\ud p\ud 2\ud and spin structure functions \ud g\ud p\ud 1\ud and \ud g\ud p\ud 2\ud over a wide kinematic range (0.05 \ud GeV\ud 2\ud

Published
2017

14. Differential cross section measurements for γn → π−p above the first nucleon resonance region

Author

Mattione, P. T., Carman, D. S., Strakovsky, I. I., Workman, R. L., Kudryavtsev, A. E., Svarc, A., Tarasov, V. E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Anefalos Pereira, S., Ball, J., Baltzell, N. A., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Cao, T., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D.G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.

Subjects
High Energy Physics::Experiment
Abstract

The quasifree \ud γ\ud d\ud →\ud π\ud −\ud p\ud (\ud p\ud )\ud differential cross section has been measured with CLAS at photon beam energies \ud E\ud γ\ud from 0.445 to 2.510 GeV (corresponding to \ud W\ud from 1.311 to 2.366 GeV) for pion center-of-mass angles \ud cos\ud θ\ud c\ud .\ud m\ud .\ud π\ud from \ud −\ud 0.72\ud to 0.92. A correction for final state interactions has been applied to these data to extract the \ud γ\ud n\ud →\ud π\ud −\ud p\ud differential cross sections. These cross sections are quoted in 8428 \ud (\ud E\ud γ\ud ,\ud cos\ud θ\ud c\ud .\ud m\ud .\ud π\ud )\ud bins, a factor of nearly 3 increase in the world statistics for this channel in this kinematic range. These new data help to constrain coupled-channel analysis fits used to disentangle the spectrum of \ud N\ud ∗\ud resonances and extract their properties. Selected photon decay amplitudes \ud N\ud ∗\ud →\ud γ\ud n\ud at the resonance poles are determined for the first time and are reported here.

Published
2017

15. Measurements of ep→e′π+π−p′ cross sections with CLAS at 1.40 GeV < W < 2.0 GeV and 2.0 GeV2 < Q2 < 5.0 GeV2

Author

Isupov, E. L., Burkert, V. D., Carman, D. S., Gothe, R. W., Hicks, K., Ishkhanov, B. S., Mokeev, V. I., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Bültmann, S., Cao, T., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Garçon, M., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Golovatch, E., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Jenkins, D., Jiang, H., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Kunkel, M., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., McKinnon, B., Mineeva, T., Mirazita, M., Montgomery, R. A., Movsisyan, A., Munevar, E., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Trivedi, A., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wei, X., Wood, M. H., Zachariou, N., and Zhang, J.

Abstract

This paper reports new exclusive cross sections for ep → ep\ud π+π−p' using the CLAS detector at Jefferson\ud Laboratory. These results are presented for the first time at photon virtualities 2.0 GeV2 < Q2 < 5.0 GeV2 in\ud the center-of-mass energy range 1.4 GeV

Published
2017

16. Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1 GeV2. II. ep→eπ0p

Author

Bosted, P. E., Kim, A., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bültmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hakobyan, H., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ireland, D. G., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klei, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V. I., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear and High Energy Physics, Economica, Socio-culturale, High Energy Physics::Experiment, RESONANCE, Nuclear Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive \ud π\ud 0\ud electroproduction reaction \ud γ\ud ∗\ud p\ud →\ud p\ud π\ud 0\ud , expanding an analysis of the \ud γ\ud ∗\ud p\ud →\ud n\ud π\ud +\ud reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are \ud 1.1\ud

Published
2017

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

Author

Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Hen, Or, Cruz Torres, Reynier, Beck, Sharon, Beck, Arie, Schmookler, Barak Abraham, Cohen, E. O., Piasetzky, E., Weinstein, L. B., Duer, M., Schmidt, A., Korover, I., Hakobyan, H., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Charles, G., Chatagnon, Pierre, Chetry, T., Ciullo, G., Clary, Brandon A., Contalbrigo, M., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, Mathieu, El Alaoui, A., Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Hafidi, K., Harrison, N., Hauenstein, F., Heddle, D., Hicks, K., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Mustapha, B., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Schumacher, R. A., Sharabian, Y. G., Sokhan, D., Sparveris, N., Stepanyan, S., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zheng, X., Zhao, Z. W., Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Hen, Or, Cruz Torres, Reynier, Beck, Sharon, Beck, Arie, Schmookler, Barak Abraham, Cohen, E. O., Piasetzky, E., Weinstein, L. B., Duer, M., Schmidt, A., Korover, I., Hakobyan, H., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Charles, G., Chatagnon, Pierre, Chetry, T., Ciullo, G., Clary, Brandon A., Contalbrigo, M., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, Mathieu, El Alaoui, A., Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Hafidi, K., Harrison, N., Hauenstein, F., Heddle, D., Hicks, K., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munoz Camacho, C., Mustapha, B., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Schumacher, R. A., Sharabian, Y. G., Sokhan, D., Sparveris, N., Stepanyan, S., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zheng, X., and Zhao, Z. W.

Abstract

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k[subscript F]). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k[subscript F], and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e′ pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states., National Science Foundation (U.S.)

Published
2018

18. Measurement of target and double-spin asymmetries for the e p → eπ+(n) reaction in the nucleon resonance region at low Q2

Author

Zheng, X., Adhikari, K. P., Bosted, P., Deur, A., Drozdov, V., El Fassi, L., Kang, Hyekoo, Kovacs, K., Kuhn, S., Long, E., Phillips, S. K., Ripani, M., Slifer, K., Smith, L. C., Adikaram, D., Akbar, Z., Amaryan, M. J., Anefalos Pereira, S., Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chen, J.-P., Chetry, T., Choi, Seonho, Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., El Alaoui, A., Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovach, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D.G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I.J.D., Markov, N., McKinnon, B., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Munoz Camacho, C., Murdoch, G., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J. W., Puckett, A. J. R., Raue, B. A., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zhang, J., and Zonta, I.

Subjects
Nuclear and High Energy Physics, Economica, Socio-culturale, High Energy Physics::Experiment, Nuclear Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract

We report measurements of target- and double-spin asymmetries for the exclusive channel ep → eπ+(n) in\ud the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These\ud asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally\ud polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous\ud CLAS publications but are extended to a low Q2 range from 0.0065 to 0.35 (GeV/c)\ud 2. The Q2 access was made\ud possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low\ud as 6◦. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis\ud prediction from SAID, and the dynamic model DMT. In many kinematic regions our results, in particular results\ud on the target asymmetry, help to constrain the polarization-dependent components of these models.

Published
2016

19. Measurements of ep→e′π+nat1.6<W<2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS

Author

Park, K, Aznauryan, Ig, Burkert, Vd, Adhikari, Kp, Amaryan, Mj, Pereira, Sa, Avakian, H, Battaglieri, M, Badui, R, Bedlinskiy, I, Biselli, As, Bono, J, Briscoe, Wj, Brooks, Wk, Carman, Ds, Celentano, A, Chandavar, S, Charles, G, Colaneri, L, Cole, Pl, Contalbrigo, M, Cortes, O, Crede, V, D'Angelo, A, Dashyan, N, De Vita, R, De Sanctis, E, Deur, A, Djalali, C, Doughty, D, Dupre, R, Egiyan, H, Alaoui, Ae, Elouadrhiri, L, Fassi, Le, Eugenio, P, Fedotov, G, Fegan, S, Fersch, R, Filippi, A, Fleming, Ja, Garillon, B, Garçon, M, Gevorgyan, N, Gilfoyle, Gp, Giovanetti, Kl, Girod, Fx, Joo, Hs, Goetz, Jt, Golovatch, E, Gothe, Rw, Griffioen, Ka, Guegan, B, Guidal, M, Guo, L, Hakobyan, H, Hanretty, C, Hattawy, M, Hicks, K, Holtrop, M, Hughes, Sm, Hyde, Ce, Ilieva, Y, Ireland, Dg, Ishkhanov, Bs, Isupov, El, Jenkins, D, Jiang, H, H. S., J, Joo, K, Joosten, S, Keller, D, Khandaker, M, Kim, A, Kim, W, Klein, A, Klein, Fj, Kubarovsky, V, Kuhn, Se, Kuleshov, Sv, Lenisa, P, Livingston, K, H. Y., L, Macgregor, Ijd, Markov, N, Martinez, D, Mckinnon, B, Mokeev, V, Montgomery, Ra, Moutarde, H, Camacho, Cm, Nadel-Turonski, P, Niccolai, S, Niculescu, G, Niculescu, I, Osipenko, M, Ostrovidov, Ai, Paolone, M, Pasyuk, E, Peng, P, Phelps, W, Phillips, Jj, Pisano, S, Pogorelko, O, Price, Jw, Procureur, S, Prok, Y, Protopopescu, D, Puckett, Ajr, Raue, Ba, Ripani, M, Rizzo, A, Rosner, G, Rossi, P, Roy, P, Sabatié, F, Salgado, C, Schott, D, Schumacher, Ra, Seder, E, Sharabian, Yg, Simonyan, A, Skorodumina, I, Smith, Es, Smith, Gd, Sparveris, N, Stoler, P, Strakovsky, Ii, Strauch, S, Sytnik, V, Taiuti, M, Tang, W, Taylor, Ce, Tian, Y, Trivedi, A, Ungaro, M, Voskanyan, H, Voutier, E, Walford, Nk, Watts, Dp, Wei, X, Weinstein, Lb, Wood, Mh, Zachariou, N, Zana, L, Zhang, J, Zhao, Zw, and Zonta, I

Subjects
RELATIVISTIC QUARK-MODEL, TRANSITION FORM-FACTORS, MESON PRODUCTION, GAMMA-ASTERISK, ELECTROPRODUCTION, PHOTOPRODUCTION, REGION, Settore FIS/04 - Fisica Nucleare e Subnucleare
Published
2015

20. Comparison of forward and backward pp pair knockout in He-3(e,e'pp)n

Author

Baghdasaryan, H., Weinstein, L. B., Laget, J. M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Ball, J., Battaglieri, M., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Sanctis, E., De Vita, R., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Fedotov, G., Gabrielyan, M. Y., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Hafidi, K., Hicks, K., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jo, H. S., Joo, K., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Lu, H. Y., MacGregor, I. J. D., McKinnon, B., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pisano, S., Pozdniakov, S., Procureur, S., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Saini, M. S., Saylor, N. A., Schott, D., Schumacher, R. A., Seraydaryan, H., Smith, E. S., Sober, D. I., Sokan, D., Stepanyan, S. S., Stepanyan, S., Strauch, S., Taiuti, M., Tang, W., Tkachenko, S., Voskanyan, H., Voutier, E., Wood, M. H., Zana, L., and Zhao, B.

Subjects
MECHANISMS, DEUTERON, Settore FIS/04 - Fisica Nucleare e Subnucleare
Published
2012

21. Measurement of the generalized form factors near threshold via gamma* p -> n pi(+) at high Q(2)

Author

Park, K., Gothe, R. W., Adhikari, K. P., Adikaram, D., Anghinolfi, M., Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Branford, D., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, Marco, Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., Vita, R. D., Sanctis, E. D., Deur, A., Djalali, C., Doughty, D., Dupre, R., Alaoui, A. E., Fassi, L. E., Eugenio, P., Fedotov, G., Fradi, A., Gabrielyan, M. Y., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Graham, L., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., H. S., Jo, Joo, K., Kalantarians, N., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Livingston, K., H. Y., Lu, I. J. D., Markov, N., Mayer, M., Mckinnon, B., Mestayer, M. D., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Nadel Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, Luciano Libero, Paremuzyan, R., Park, S., Pereira, S. A., Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Ricco, G., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Y., Tkachenko, S., Trivedi, A., Ungaro, M., Vernarsky, B., Vlassov, A. V., Voutier, E., Watts, D. P., Weygand, D. P., Wood, M. H., Zachariou, N., Zhao, B., and Zhao, Z. W.

Subjects
QUANTUM CHROMODYNAMICS, PI-0, PION ELECTROPRODUCTION, NUCLEONS, PROTON, PHOTOPRODUCTION, Settore FIS/04 - Fisica Nucleare e Subnucleare
Published
2012

22. Polarization transfer in the He4(e→,e ′p→)H3 Reaction at Q2=0.8 and 1.3(GeV/c) 2

Author

Paolone, M., Udías, J.M., Vignote, J.R., and Zhan, X.

Subjects
Nuclear Theory, Physics::Accelerator Physics, Nuclear Experiment
Abstract

Proton recoil polarization was measured in the quasielastic He 4(e→,e′p→)H3 reaction at Q2=0.8 and 1.3(GeV/c)2 with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the H1(e→,e ′p→) reaction, contradicting a relativistic distorted-wave approximation and favoring either the inclusion of medium-modified proton form factors predicted by the quark-meson coupling model or a spin-dependent charge-exchange final-state interaction. For the first time, the polarization-transfer ratio is studied as a function of the virtuality of the proton. © 2010 The American Physical Society., Supported by the U.S. Department of Energy and the U.S. National Science Foundation. Jefferson Science Associates operates theThomas Jefferson National Accelerator Facility under DOE Contract No. DE-AC05-06OR23177.

Published
2010

23. Search for a New Gauge Boson in Electron-Nucleus Fixed-Target Scattering by the APEX Experiment

Author

Massachusetts Institute of Technology. Laboratory for Nuclear Science, Sulkosky, Vincent, Kelleher, Aidan Michael, Huang, J., Hansen, J.O., Iqbal, S., Abrahamyan, S., Ahmed, Z., Allada, Kalyan C., Anez, D., Averett, T., Barbieri, A., Bartlett, K., Beacham, J., Bono, J., Boyce, J. R., Brindza, P., Camsonne, A., Cranmer, K., Dalton, M. M., de Jager, C. W., Donaghy, J., Essig, R., Field, C., Folts, E., Gasparian, A., Goeckner-Wald, N., Gomez, J., Graham, M., Higinbotham, D. W., Holmstrom, T., Jaros, J., Jensen, E., Khandaker, M., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Mammei, J., Markowitz, P., Maruyama, T., Maxwell, V., Mayilyan, S., McDonald, J., Michaels, R., Moffeit, K., Nelyubin, V., Odian, A., Oriunno, M., Partridge, R., Paolone, M., Piasetzky, E., Pomerantz, I., Qiang, Y., Riordan, S., Roblin, Y., Sawatzky, B., Schuster, P., Segal, J., Selvy, L., Shahinyan, A., Subedi, R., Stepanyan, S., Toro, N., Walz, D., Wojtsekhowski, B., Zhang, J., Massachusetts Institute of Technology. Laboratory for Nuclear Science, Sulkosky, Vincent, Kelleher, Aidan Michael, Huang, J., Hansen, J.O., Iqbal, S., Abrahamyan, S., Ahmed, Z., Allada, Kalyan C., Anez, D., Averett, T., Barbieri, A., Bartlett, K., Beacham, J., Bono, J., Boyce, J. R., Brindza, P., Camsonne, A., Cranmer, K., Dalton, M. M., de Jager, C. W., Donaghy, J., Essig, R., Field, C., Folts, E., Gasparian, A., Goeckner-Wald, N., Gomez, J., Graham, M., Higinbotham, D. W., Holmstrom, T., Jaros, J., Jensen, E., Khandaker, M., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Mammei, J., Markowitz, P., Maruyama, T., Maxwell, V., Mayilyan, S., McDonald, J., Michaels, R., Moffeit, K., Nelyubin, V., Odian, A., Oriunno, M., Partridge, R., Paolone, M., Piasetzky, E., Pomerantz, I., Qiang, Y., Riordan, S., Roblin, Y., Sawatzky, B., Schuster, P., Segal, J., Selvy, L., Shahinyan, A., Subedi, R., Stepanyan, S., Toro, N., Walz, D., Wojtsekhowski, B., and Zhang, J.

Published
2012

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

Author

Hobart A, Niccolai S, Čuić M, Kumerički K, Achenbach P, Alvarado JS, Armstrong WR, Atac H, Avakian H, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Benkel B, Benmokhtar F, Bianconi A, Biselli AS, Boiarinov S, Bondi M, Booth WA, Bossù F, Brinkmann KT, Briscoe WJ, Brooks WK, Bueltmann S, Burkert VD, Cao T, Capobianco R, Carman DS, Chatagnon P, Ciullo G, Cole PL, 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 AE, Fassi LE, Elouadrhiri L, Fegan S, Filippi A, Fogler C, Gates K, Gavalian G, Gilfoyle GP, Glazier D, Gothe RW, Gotra Y, Guidal M, Hafidi K, Hakobyan H, Hattawy M, Hauenstein F, Heddle D, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jiang H, Jo HS, Joo K, Kageya T, Kim A, Kim W, Klimenko V, Kripko A, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lee S, Lenisa P, Li X, MacGregor IJD, Marchand D, Mascagna V, Maynes M, McKinnon B, Meziani ZE, Migliorati S, Milner RG, Mineeva T, Mirazita M, Mokeev V, Camacho CM, Nadel-Turonski P, Naidoo P, Neupane K, Niculescu G, Osipenko M, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Paul SJ, Phelps W, Pilleux N, Pokhrel M, Rafael SP, Poudel J, Price JW, Prok Y, Reed T, Richards J, Ripani M, Ritman J, Rossi P, Golubenko AA, Salgado C, Schadmand S, Schmidt A, Scott MBC, Seroka EM, Sharabian YG, Shirokov EV, Shrestha U, Sparveris N, Spreafico M, Stepanyan S, Strakovsky II, Strauch S, Tan JA, Trotta N, Tyson R, Ungaro M, Vallarino S, Venturelli L, Tommaso V, Voskanyan H, Voutier E, Watts DP, Wei X, Williams R, Wood MH, Xu L, Zachariou N, Zhang J, Zhao ZW, and Zurek M

Abstract

Measuring deeply virtual Compton scattering (DVCS) 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 Compton form factors H and E.

Published
2024
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25. First Measurement of Hard Exclusive π^{-}Δ^{++} Electroproduction Beam-Spin Asymmetries off the Proton.

Author

Diehl S, Trotta N, Joo K, Achenbach P, Akbar Z, Armstrong WR, Atac H, Avakian H, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bossù F, Brinkmann KT, Briscoe WJ, Bulumulla D, Burkert V, Capobianco R, Carman DS, Carvajal JC, Celentano A, Charles G, Chatagnon P, Chesnokov V, Ciullo G, Cole PL, Contalbrigo M, Costantini G, Crede V, D'Angelo A, Dashyan N, De Vita R, Deur A, Djalali C, Dupre R, Ehrhart M, El Alaoui A, El Fassi L, Elouadrhiri L, Fegan S, Filippi A, Gavalian G, Glazier DI, Golubenko AA, Gosta G, Gothe RW, Gotra Y, Griffioen K, Hafidi K, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Hobart A, Holtrop M, Illari I, Ireland DG, Isupov EL, Jo HS, Johnston R, Keller D, Khachatryan M, Khanal A, Kim A, Kim W, Klimenko V, Kripko A, Kubarovsky V, Kuhn SE, Lagerquist V, Lanza L, Leali M, Lee S, Lenisa P, Li X, MacGregor IJD, Marchand D, Mascagna V, Matousek G, McKinnon B, McLauchlin C, Meziani ZE, Migliorati S, Milner RG, Mineeva T, Mirazita M, Mokeev V, Moran P, Munoz Camacho C, Naidoo P, Neupane K, Niccolai S, Niculescu G, Osipenko M, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Paul SJ, Phelps W, Pilleux N, Pokhrel M, Poudel J, Price JW, Prok Y, Radic A, Raue BA, Reed T, Richards J, Ripani M, Ritman J, Rossi P, Sabatié F, Salgado C, Schadmand S, Schmidt A, Sharabian YG, 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 DP, Wei X, Williams R, Wishart R, Wood MH, Yurov M, Zachariou N, Zhao ZW, and Zurek M

Abstract

The polarized cross-section ratio σ&#95;{LT^{'}}/σ&#95;{0} from hard exclusive π^{-}Δ^{++} 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→Δ^{++} transition generalized parton distributions. A comparison to existing results for hard exclusive π^{+}n and π^{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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26. First CLAS12 Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries in the Extended Valence Region.

Author

Christiaens G, Defurne M, Sokhan D, Achenbach P, Akbar Z, Amaryan MJ, Atac H, Avakian H, Gayoso CA, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benkel B, Benmokhtar F, Bianconi A, Biselli AS, Bondi M, Booth WA, Bossù F, Boiarinov S, Brinkmann KT, Briscoe WJ, Bueltmann S, Bulumulla D, Burkert VD, Cao T, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chesnokov V, Chetry T, Ciullo G, Clash G, Cole PL, 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 AE, Fassi LE, Elouadrhiri L, Fegan S, Filippi A, Gates K, Gavalian G, Ghandilyan Y, Gilfoyle GP, Girod FX, Glazier DI, Golubenko AA, Gosta G, Gothe RW, Gotra Y, Griffioen KA, Guidal M, Hafidi K, Hakobyan H, Hattawy M, Hauenstein F, Hayward TB, Heddle D, Hobart A, Holmberg DE, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jo HS, Keller D, Khachatryan M, Khanal A, Kim W, Kripko A, Kubarovsky V, Kuhn SE, Lagerquist V, Lanza L, Kabir ML, Leali M, Lee S, Lenisa P, Li X, Livingston K, MacGregor IJD, Marchand D, Mascagna V, Matousek G, McKinnon B, McLauchlin C, Meziani ZE, Migliorati S, Milner RG, Mineeva T, Mirazita M, Mokeev V, Molina E, Camacho CM, Nadel-Turonski P, Naidoo P, Neupane K, Niccolai S, Nicol M, Niculescu G, Osipenko M, Ouillon M, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Paul SJ, Phelps W, Pilleux N, Pokhrel M, Poudel J, Price JW, Prok Y, Radic A, Ramasubramanian N, Raue BA, Reed T, Richards J, Ripani M, Ritman J, Rossi P, Sabatié F, Salgado C, Schadmand S, Schmidt A, Scott MBC, Sharabian YG, Shirokov EV, Shrestha U, Simmerling P, Sparveris N, Spreafico M, Stepanyan S, Strakovsky II, Strauch S, Tan JA, Trotta N, Turisini M, Tyson R, Ungaro M, Vallarino S, Venturelli L, Voskanyan H, Voutier E, Watts DP, Wei X, Williams R, Wishart R, Wood MH, Zachariou N, Zhang J, Zhao ZW, Ziegler V, and Zurek M

Abstract

Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions 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 unpolarized protons. The results greatly extend the Q^{2} and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.

Published
2023
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27. First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions.

Author

Chetry T, El Fassi L, Brooks WK, Dupré R, El Alaoui A, Hafidi K, Achenbach P, Adhikari KP, Akbar Z, Armstrong WR, Arratia M, Atac H, Avakian H, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benkel B, Benmokhtar F, Bianconi A, Biselli AS, Bondi M, Booth WA, Bossù F, Boiarinov S, Brinkmann KT, Briscoe WJ, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chesnokov V, Ciullo G, Cole PL, 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 GP, Glazier DI, Golubenko AA, Gosta G, Gothe RW, Griffioen KA, Guidal M, Guo L, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Hobart A, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jenkins D, Jo HS, Kabir ML, Khanal A, Khandaker M, Kim A, Kim W, Klein FJ, Kripko A, Kubarovsky V, Lagerquist V, Lanza L, Leali M, Lee S, Lenisa P, Li X, Livingston K, MacGregor IJD, Marchand D, Mascagna V, McKinnon B, McLauchlin C, Meziani ZE, Migliorati S, Mineeva T, Mirazita M, Mokeev V, Munoz Camacho C, Nadel-Turonski P, Neupane K, Niccolai S, Nicol M, Niculescu G, Osipenko M, Ostrovidov AI, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Paul SJ, Phelps W, Pilleux N, Pokhrel M, Poudel J, Price JW, Prok Y, Raue BA, Reed T, Richards J, Ripani M, Ritman J, Rosner G, Sabatié F, Salgado C, Schadmand S, Schmidt A, Schumacher RA, Sharabian YG, Shirokov EV, Shrestha U, Simmerling P, Sokhan D, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Tan JA, Trotta N, Tyson R, Ungaro M, Vallarino S, Venturelli L, Voskanyan H, Voutier E, Wei X, Weinstein LB, Williams R, Wishart R, Wood MH, Yurov M, Zachariou N, Zhao ZW, and Zurek M

Abstract

We report results of Λ 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 Λ 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.

Published
2023
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28. Observation of Correlations between Spin and Transverse Momenta in Back-to-Back Dihadron Production at CLAS12.

Author

Avakian H, Hayward TB, Kotzinian A, Armstrong WR, Atac H, Ayerbe Gayoso C, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benkel B, Benmokhtar F, Bianconi A, Biondo L, Biselli AS, Bondi M, Boiarinov S, Bossù F, Brinkman KT, Briscoe WJ, Brooks WK, Bueltmann S, Bulumulla D, Burkert VD, Capobianco R, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chesnokov V, Chetry T, Ciullo G, Cole PL, Contalbrigo M, Costantini G, D'Angelo A, Dashyan N, De Vita R, Defurne M, Deur A, Diehl S, Dilks C, Djalali C, Dupre R, Egiyan H, El Alaoui A, El Fassi L, Elouadrhiri L, Fegan S, Filippi A, Forest T, Gates K, Gavalian G, Ghandilyan Y, Glazier DI, Golubenko AA, Gosta G, Gothe RW, Gotra Y, Griffioen KA, Guidal M, Hakobyan H, Hattawy M, Hauenstein F, Heddle D, Hobart A, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Isupov EL, Jo HS, Johnston R, Joo K, Kabir ML, Keller D, Khachatryan M, Khanal A, Kim A, Kim W, Klimenko V, Kripko A, Kubarovsky V, Kuhn SE, Lagerquist V, Lanza L, Leali M, Lee S, Lenisa P, Li X, MacGregor IJD, Marchand D, Mascagna V, McKinnon B, Migliorati S, Mineeva T, Mirazita M, Mokeev V, Montgomery RA, Munoz Camacho C, Nadel-Turonski P, Naidoo P, Neupane K, Nguyen D, Niccolai S, Nicol M, Niculescu G, Osipenko M, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Paul SJ, Phelps W, Pilleux N, Pogorelko O, Pokhrel M, Poudel J, Price JW, Prok Y, Raue BA, Reed T, Richards J, Ripani M, Ritman J, Rossi P, Sabatié F, Salgado C, Schmidt A, Sharabian YG, Shirokov EV, Shrestha U, Simmerling P, Sokhan D, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Tan JA, Trotta N, Tyson R, Ungaro M, Vallarino S, Venturelli L, Voskanyan H, Vossen A, Voutier E, Watts DP, Wei X, Wishart R, Wood MH, Zachariou N, Zhao ZW, and Zurek M

Abstract

We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction in the deep inelastic scattering process. In this reaction, two hadrons are produced in opposite hemispheres along the z axis in the virtual photon-target nucleon 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 nonzero sinΔϕ modulations in ep→e^{'}pπ^{+}X events, where Δϕ 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 unexplored 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.

Published
2023
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29. Observation of Azimuth-Dependent Suppression of Hadron Pairs in Electron Scattering off Nuclei.

Author

Paul SJ, Morán S, Arratia M, El Alaoui A, Hakobyan H, Brooks W, Amaryan MJ, Armstrong WR, Atac H, Baashen L, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benkel B, Benmokhtar F, Bianconi A, Biondo L, Biselli AS, Bondi M, Bossù F, Boiarinov S, Brinkmann KT, Briscoe WJ, Bulumulla D, Burkert VD, Capobianco R, Carman DS, Celentano A, Chesnokov V, Chetry T, Ciullo G, Cole PL, Contalbrigo M, Costantini G, D'Angelo A, Dashyan N, De Vita R, Defurne M, Deur A, Diehl S, Dilks C, Djalali C, Dupre R, Egiyan H, El Fassi L, Eugenio P, Fegan S, Filippi A, Gavalian G, Ghandilyan Y, Gilfoyle GP, Golubenko AA, Gosta G, Gothe RW, Griffioen KA, Guidal M, Hattawy M, Hayward TB, Heddle D, Hobart A, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jo HS, 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 IJD, Marchand D, Mascagna V, McKinnon B, Meziani ZE, Migliorati S, Milner RG, Mineeva T, Mirazita M, Mokeev VI, Moran P, Munoz Camacho C, Neupane K, Nguyen D, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Phelps W, Pilleux N, Pocanic D, Pogorelko O, Pokhrel M, Poudel J, Price JW, Prok Y, Raue BA, Reed T, Ripani M, Rosner G, Sabatié F, Salgado C, Schmidt A, Schumacher RA, Sharabian YG, Shirokov EV, Shrestha U, Simmerling P, Sokhan D, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Tan JA, Tyson R, Ungaro M, Vallarino S, Venturelli L, Voskanyan H, Voutier E, Wei X, Wishart R, Wood MH, Zachariou N, Zhao ZW, Ziegler V, and Zurek M

Abstract

We present the first measurement of dihadron 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.

Published
2022
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30. Measurement of the Nucleon F&#95;{2}^{n}/F&#95;{2}^{p} Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment.

Author

Abrams D, Albataineh H, Aljawrneh BS, Alsalmi S, Androic D, Aniol K, Armstrong W, Arrington J, Atac H, Averett T, Gayoso CA, Bai X, Bane J, Barcus S, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Blyth D, Boeglin W, Bulumulla D, Butler J, Camsonne A, Carmignotto M, Castellanos J, Chen JP, Cohen EO, Covrig S, Craycraft K, Cruz-Torres R, Dongwi B, Duran B, Dutta D, Fuchey E, Gal C, Gautam TN, Gilad S, Gnanvo K, Gogami T, Gomez J, Gu C, Habarakada A, Hague T, Hansen JO, Hattawy M, Hauenstein F, Higinbotham DW, Holt RJ, Hughes EW, Hyde C, Ibrahim H, Jian S, Joosten S, Karki A, Karki B, Katramatou AT, Keith C, Keppel C, Khachatryan M, Khachatryan V, Khanal A, Kievsky A, King D, King PM, Korover I, Kulagin SA, Kumar KS, Kutz T, Lashley-Colthirst N, Li S, Li W, Liu H, Liuti S, Liyanage N, Markowitz P, McClellan RE, Meekins D, Beck SM, Meziani ZE, Michaels R, Mihovilovic M, Nelyubin V, Nguyen D, Nuruzzaman, Nycz M, Obrecht R, Olson M, Owen VF, Pace E, Pandey B, Pandey V, Paolone M, Papadopoulou A, Park S, Paul S, Petratos GG, Petti R, Piasetzky E, Pomatsalyuk R, Premathilake S, Puckett AJR, Punjabi V, Ransome RD, Rashad MNH, Reimer PE, Riordan S, Roche J, Salmè G, Santiesteban N, Sawatzky B, Scopetta S, Schmidt A, Schmookler B, Segal J, Segarra EP, Shahinyan A, Širca S, Sparveris N, Su T, Suleiman R, Szumila-Vance H, Tadepalli AS, Tang L, Tireman W, Tortorici F, Urciuoli GM, Wojtsekhowski B, Wood S, Ye ZH, Ye ZY, and Zhang J

Abstract

The ratio of the nucleon F&#95;{2} structure functions, F&#95;{2}^{n}/F&#95;{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19

Published
2022
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31. Multidimensional, High Precision Measurements of Beam Single Spin Asymmetries in Semi-inclusive π^{+} 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, Ayerbe Gayoso C, Baltzell NA, Barion L, Bastami S, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bondi M, Bossù F, Boiarinov S, Brinkmann KT, Briscoe WJ, Brooks W, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chetry T, Ciullo G, Clark L, Clary BA, Cole PL, 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, Egiyan H, Ehrhart M, El Alaoui A, El Fassi L, Elouadrhiri L, Fegan S, Filippi A, Forest T, Gavalian G, Gilfoyle GP, Girod FX, Glazier DI, Golubenko AA, Gothe RW, Gotra Y, Griffioen KA, Guidal M, Hafidi K, Hakobyan H, Hattawy M, Hauenstein F, Hayward TB, Heddle D, Hicks K, Hobart A, Holtrop M, Hyde CE, Ireland DG, Isupov EL, Jo HS, Johnston R, Joosten S, Keller D, Khachatryan M, Khanal A, Kim W, Kripko A, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lee S, Lenisa P, Livingston K, Lu Z, MacGregor IJD, Marchand D, Markov N, Marsicano L, Mascagna V, McKinnon B, Meziani ZE, Milner RG, Mineeva T, Mirazita M, Mokeev V, Moran P, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Naidoo P, Nanda S, Neupane K, Niccolai S, Niculescu G, O'Connell TR, Osipenko M, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Phelps W, Pogorelko O, Prok Y, Prokudin A, Raue BA, Ripani M, Ritman J, Rizzo A, Roberts CD, Rossi P, Rowley J, Sabatié F, Salgado C, Schmidt A, Segarra EP, Sharabian YG, Shrestha U, Simmerling P, Sokhan D, Soto O, Sparveris N, Stepanyan S, Stoler P, Strakovsky II, Strauch S, Tezgin K, Thornton A, Tyler N, Tyson R, Ungaro M, Venturelli L, Voskanyan H, Vossen A, Voutier E, Watts DP, Wei K, Wei X, Xu SS, Yale B, Zachariou N, and Zhang J

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 π^{+} 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&#95;{LU}^{sinϕ}/F&#95;{UU} has been determined, where F&#95;{LU}^{sinϕ} 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
2022
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32. Improved Λp Elastic Scattering Cross Sections between 0.9 and 2.0  GeV/c as a Main Ingredient of the Neutron Star Equation of State.

Author

Rowley J, Compton N, Djalali C, Hicks K, Price J, Zachariou N, Adhikari KP, Armstrong WR, Atac H, Baashen L, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biondo L, Biselli AS, Bondi M, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chesnokov V, Chetry T, Ciullo G, Clark L, Cole PL, Contalbrigo M, Costantini G, Crede V, D'Angelo A, Dashyan N, De Vita R, Defurne M, Deur A, Diehl S, Dupré R, Egiyan H, Ehrhart M, El Alaoui A, El Fassi L, Eugenio P, Fedotov G, Fegan S, Fersch R, Filippi A, Fradi A, Gavalian G, Girod FX, Glazier DI, Golubenko A, Gothe RW, Griffioen K, Guo L, Hafidi K, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Hobart A, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jenkins D, Jo HS, Joo K, Keller D, Khanal A, Khandaker M, Kim A, Korover I, Kripko A, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Markov N, Marsicano L, Mascagna V, McCracken ME, McKinnon B, McLauchlin C, Meziani ZE, Migliorati S, Mineeva T, Mirazita M, Mokeev V, Munevar E, Munoz Camacho C, Nadel-Turonski P, Neupane K, Niccolai S, Niculescu G, O'Connell TR, Osipenko M, Ostrovidov AI, Pandey P, Paolone M, Pappalardo LL, Pasyuk E, Pogorelko O, Prok Y, Reed T, Ripani M, Ritman J, Rizzo A, Rosner G, Sabatie F, Salgado C, Schmidt A, Schumacher RA, Sharabian YG, Shrestha U, Sokhan D, Soto O, Sparveris N, Strakovsky II, Strauch S, Tyson R, Ungaro M, Venturelli L, Voskanyan H, Vossen A, Voutier E, Watts DP, Wei K, Wei X, Wishart R, Wood MH, Yale B, Yurov M, Zhang J, and Zhao ZW

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. Yet, compared to other elastic scattering processes, there is very little data on Λ-N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the Λp→Λp elastic scattering cross section in the incident Λ momentum range 0.9-2.0  GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments.

Published
2021
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33. First Measurement of Timelike Compton Scattering.

Author

Chatagnon P, Niccolai S, Stepanyan S, Amaryan MJ, Angelini G, Armstrong WR, Atac H, Ayerbe Gayoso C, Baltzell NA, Barion L, Bashkanov M, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biondo L, Biselli AS, Bondi M, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Caudron M, Celentano A, Chetry T, Ciullo G, Clark L, Cole PL, Contalbrigo M, Costantini G, Crede V, D'Angelo A, Dashyan N, Defurne M, De Vita R, Deur A, Diehl S, Djalali C, Dupré R, Egiyan H, Ehrhart M, El Alaoui A, El Fassi L, Elouadrhiri L, Fegan S, Fersch R, Filippi A, Gavalian G, Ghandilyan Y, Gilfoyle GP, Girod FX, Glazier DI, Golubenko AA, Gothe RW, Gotra Y, Griffioen KA, Guidal M, Guo L, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Hobart A, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Isupov EL, Jo HS, Joo K, Kabir ML, Keller D, Khachatryan G, Khanal A, Kim A, Kim W, Kripko A, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lee S, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Marsicano L, Mascagna V, McKinnon B, McLauchlin C, Migliorati S, Mirazita M, Mokeev V, Montgomery RA, Munoz Camacho C, Nadel-Turonski P, Naidoo P, Neupane K, O'Connell TR, Osipenko M, Ouillon M, Pandey P, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Phelps W, Pogorelko O, Poudel J, Price JW, Prok Y, Raue BA, Reed T, Ripani M, Rizzo A, Rossi P, Rowley J, Sabatié F, Schmidt A, Segarra EP, Sharabian YG, Shirokov EV, Shrestha U, Sokhan D, Soto O, Sparveris N, Strakovsky II, Strauch S, Tyler N, Tyson R, Ungaro M, Vallarino S, Venturelli L, Voskanyan H, Vossen A, Voutier E, Watts DP, Wei K, Wei X, Wishart R, Yale B, Zachariou N, Zhang J, and Zhao ZW

Abstract

We present the first measurement of the timelike Compton scattering process, γp→p^{'}γ^{*}(γ^{*}→e^{+}e^{-}), obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities 2.25

Published
2021
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34. Observation of Beam Spin Asymmetries in the Process ep→e^{'}π^{+}π^{-}X with CLAS12.

Author

Hayward TB, Dilks C, Vossen A, Avakian H, Adhikari S, Angelini G, Arratia M, Atac H, Ayerbe Gayoso C, Baltzell NA, Barion L, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bondì M, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chetry T, Ciullo G, Clary BA, Cole PL, Contalbrigo M, Costantini G, Crede V, D'Angelo A, Dashyan N, De Vita R, Defurne M, Deur A, Diehl S, Djalali C, Dupre R, Dugger M, Egiyan H, Ehrhart M, El Alaoui A, El Fassi L, Elouadrhiri L, Fegan S, Filippi A, Forest TA, Gavalian G, Gilfoyle GP, Girod FX, Glazier DI, Golubenko AA, Gothe RW, Gotra Y, Griffioen KA, Guidal M, Hafidi K, Hakobyan H, Hattawy M, Hauenstein F, Hicks K, Hobart A, Holtrop M, Ireland DG, Isupov EL, Jo HS, Joo K, Joosten S, Keller D, Khachatryan M, Khanal A, Kim A, Kim W, Kripko A, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lee S, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Markov N, Marsicano L, Mascagna V, McKinnon B, Meziani ZE, Mirazita M, Mokeev V, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Naidoo P, Nanda S, Neupane K, Niccolai S, Niculescu G, O'Connell TR, Osipenko M, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Phelps W, Pogorelko O, Prok Y, Raue BA, Ripani M, Ritman J, Rizzo A, Rossi P, Rowley J, Sabatié F, Salgado C, Schmidt A, Segarra EP, Sharabian YG, Shrestha U, Sokhan D, Soto O, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Thornton A, Tyler N, Tyson R, Ungaro M, Venturelli L, Voskanyan H, Voutier E, Watts DP, Wei K, Wei X, Wood MH, Yale B, Zachariou N, and Zhang J

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&#95;{1}^{⊥}. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark.

Published
2021
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35. Photoproduction of the f&#95;{2}(1270) Meson Using the CLAS Detector.

Author

Carver M, Celentano A, Hicks K, Marsicano L, Mathieu V, Pilloni A, Adhikari KP, Adhikari S, Amaryan MJ, Angelini G, Atac H, Baltzell NA, Barion L, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bondi M, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Chatagnon P, Chetry T, Ciullo G, Clark L, Clary BA, Cole PL, Contalbrigo M, Crede V, D'Angelo A, Dashyan N, De Vita R, Defurne M, Deur A, Diehl S, Djalali C, Dugger M, Dupre R, Egiyan H, Ehrhart M, Alaoui AE, Fassi LE, Eugenio P, Fedotov G, Fegan S, Filippi A, Gavalian G, Gevorgyan N, Gilfoyle GP, Girod FX, Gothe RW, Griffioen KA, Hafidi K, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Holtrop M, Huang Q, Hyde CE, Ilieva Y, Ireland DG, Isupov EL, Jenkins D, Jo HS, Joo K, Joosten S, Keller D, Khanal A, Khandaker M, Kim A, Kim CW, Klein FJ, Kripko A, Kubarovsky V, Lanza L, Leali M, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Mascagna V, McCracken ME, McKinnon B, Meziani ZE, Mokeev V, Movsisyan A, Munevar E, Camacho CM, Nadel-Turonski P, Neupane K, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Phelps W, Pogorelko O, Prok Y, Protopopescu D, Ripani M, Ritchie BG, Ritman J, Rizzo A, Rosner G, Rowley J, Sabatié F, Salgado C, Schmidt A, Schumacher RA, Sharabian YG, Shrestha U, Sokhan D, Soto O, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Tyler N, Tyson R, Ungaro M, Venturelli L, Voskanyan H, Voutier E, Watts DP, Wei K, Wei X, Yale B, Zachariou N, Zhang J, and Zhao ZW

Abstract

The quark structure of the f&#95;{2}(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq[over ¯]) resonance with quantum numbers J^{PC}=2^{++}. Recently, it was proposed that the f&#95;{2}(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρ→π^{+}π^{-}, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γp→π^{0}π^{0}p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f&#95;{2}(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.

Published
2021
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36. Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs.

Author

Mirazita M, Avakian H, Courtoy A, Pisano S, Adhikari S, Amaryan MJ, Angelini G, Atac H, Baltzell NA, Barion L, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chetry T, Ciullo G, Clary B, Cole PL, 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 AE, Fassi LE, Eugenio P, Fegan S, Fersch R, Filippi A, Forest TA, Ghandilyan Y, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Glazier DI, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guo L, Hafidi K, Hakobyan H, Hattawy M, Hayward TB, Heddle D, Hicks K, Hobart A, Holtrop M, Huang Q, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jenkins D, Jo HS, Joo K, Keller D, Khanal A, Khandaker M, Kim CW, Kim W, Klein FJ, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Markov N, Marsicano L, Mascagna V, McKinnon B, Milner RG, Mineeva T, Mokeev V, Mullen C, Camacho CM, Neupane K, Niculescu G, O'Connell T, Osipenko M, Paolone M, Pappalardo LL, Paremuzyan R, Park K, Pasyuk E, Phelps W, Pocanic D, Pogorelko O, Poudel J, Prok Y, Raue BA, Ripani M, Ritman J, Rizzo A, Rossi P, Sabatié F, Salgado C, Schmidt A, Schumacher RA, Sharabian YG, Shrestha U, Soto O, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Tyler N, Ungaro M, Venturelli L, Voskanyan H, Vossen A, Voutier E, Watts D, Wei K, Wei X, Wood MH, Yale B, Zachariou N, Zhang J, and Zhao ZW

Abstract

A first measurement of the longitudinal beam spin asymmetry A&#95;{LU} in the semi-inclusive electroproduction of pairs of charged pions is reported. A&#95;{LU} 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 A&#95;{LU}^{sinϕ&#95;{R}} moments are extracted for the kinematic variables of interest in the valence quark region. The understanding of dihadron production is essential for the interpretation of observables in single-hadron production in semi-inclusive DIS, and pioneering measurements of single-spin asymmetries in dihadron production open a new avenue in studies of QCD dynamics.

Published
2021
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37. Extraction of Beam-Spin Asymmetries from the Hard Exclusive π^{+} 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 KP, Adhikari S, Amaryan MJ, Angelini G, Asryan G, Atac H, Barion L, Battaglieri M, Bedlinskiy I, Benmokhtar F, Bianconi A, Biselli AS, Bossù F, Boiarinov S, Briscoe WJ, Brooks WK, Bulumulla D, Burkert VD, Carman DS, Carvajal JC, Celentano A, Chatagnon P, Chetry T, Ciullo G, Clark L, Cole PL, 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, El Alaoui A, El Fassi L, Eugenio P, Filippi A, Forest TA, Ghandilyan Y, Gilfoyle GP, Giovanetti KL, Girod FX, Glazier DI, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guo L, Hakobyan H, Harrison N, Hattawy M, Hayward TB, Heddle D, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jenkins D, Jo HS, Joosten S, Keller D, Khachatryan M, Khanal A, Khandaker M, Kim CW, Kim W, Kubarovsky V, Kuhn SE, Lanza L, Leali M, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Markov N, Marsicano L, Mascagna V, McKinnon B, Meziani ZE, Mineeva T, Mirazita M, Mokeev V, Munoz Camacho C, Nadel-Turonski P, Niculescu G, Osipenko M, Paolone M, Pappalardo LL, Pasyuk E, Phelps W, Pogorelko O, Price JW, Prok Y, Raue BA, Ripani M, Rizzo A, Rossi P, Rowley J, Sabatié F, Salgado C, Schmidt A, Schumacher RA, Sharabian YG, Shrestha U, Soto O, Sparveris N, Stepanyan S, Stoler P, Strakovsky II, Strauch S, Tan JA, Tyler N, Ungaro M, Venturelli L, Voskanyan H, Voutier E, Watts DP, Wei X, Wood MH, Zachariou N, Zhang J, and Zhao ZW

Abstract

We have measured beam-spin asymmetries to extract the sinϕ moment A&#95;{LU}^{sinϕ} from the hard exclusive e[over →]p→e^{'}nπ^{+} 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&#95;{LU}^{sinϕ} 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&#95;{LU}^{sinϕ} to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter 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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38. New Insight in the Q^{2} Dependence of Proton Generalized Polarizabilities.

Author

Beričič J, Correa L, Benali M, Achenbach P, Ayerbe Gayoso C, Bernauer JC, Blomberg A, Böhm R, Bosnar D, Debenjak L, Denig A, Distler MO, Downie EJ, Esser A, Fonvieille H, Friščić I, Kegel S, Kohl Y, Makek M, Merkel H, Middleton DG, Mihovilovič M, Müller U, Nungesser L, Paolone M, Pochodzalla J, Sánchez Majos S, Schlimme BS, Schoth M, Schulz F, Sfienti C, Širca S, Sparveris N, Štajner S, Thiel M, Tyukin A, Weber A, and Weinriefer M

Abstract

Virtual Compton scattering on the proton has been investigated at three yet unexplored values of the four-momentum transfer Q^{2}: 0.10, 0.20, and 0.45  GeV^{2}, at the Mainz Microtron. Fits performed using either the low-energy theorem or dispersion relations allowed the extraction of the structure functions P&#95;{LL}-P&#95;{TT}/ε and P&#95;{LT}, as well as the electric and magnetic generalized polarizabilities α&#95;{E1}(Q^{2}) and β&#95;{M1}(Q^{2}). These new results show a smooth and rapid falloff of α&#95;{E1}(Q^{2}), in contrast to previous measurements at Q^{2}=0.33  GeV^{2}, and provide for the first time a precise mapping of β&#95;{M1}(Q^{2}) in the low-Q^{2} region.

Published
2019
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39. Direct Observation of Proton-Neutron Short-Range Correlation Dominance in Heavy Nuclei.

Author

Duer M, Schmidt A, Pybus JR, Segarra EP, Hrnjic A, Denniston AW, Weiss R, Hen O, Piasetzky E, Weinstein LB, Barnea N, Korover I, Cohen EO, Hakobyan H, Adhikari S, Angelini G, Battaglieri M, Beck A, Bedlinskiy I, Biselli AS, Boiarinov S, Brooks W, Burkert VD, Cao F, Carman DS, Celentano A, Chetry T, Ciullo G, Clark L, Cole PL, Contalbrigo M, Cortes O, Crede V, Cruz Torres R, D'Angelo A, Dashyan N, De Sanctis E, De Vita R, Deur A, Diehl S, Djalali C, Dupre R, Duran B, Egiyan H, El Alaoui A, El Fassi L, Eugenio P, Filippi A, Forest TA, Gilfoyle GP, Giovanetti KL, Girod FX, Golovatch E, Gothe RW, Griffioen KA, Guo L, Hafidi K, Hanretty C, Harrison N, Hattawy M, Hauenstein F, Hayward TB, Heddle D, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jo HS, Joo K, Kabir ML, Keller D, Khachatryan M, Khanal A, Khandaker M, Kim W, Klein FJ, Kubarovsky V, Kuhn SE, Lanza L, Laskaris G, Lenisa P, Livingston K, MacGregor IJD, Marchand D, Markov N, McKinnon B, Mey-Tal Beck S, Mirazita M, Mokeev V, Montgomery RA, Movsisyan A, Munoz Camacho C, Mustapha B, Nadel-Turonski P, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Paolone M, Paremuzyan R, Park K, Pasyuk E, Patsyuk M, Phelps W, Pogorelko O, Prok Y, Protopopescu D, Ripani M, Rizzo A, Rosner G, Rossi P, Sabatié F, Schmookler BA, Schumacher RA, Sharabian Y, Skorodumina I, Sokhan D, Sparveris N, Stepanyan S, Strauch S, Taiuti M, Tan JA, Tyler N, Ungaro M, Voskanyan H, Voutier E, Wang R, Wei X, Wood MH, Zachariou N, Zhang J, Zhao ZW, and Zheng X

Abstract

We measured the triple coincidence A(e,e^{'}np) and A(e,e^{'}pp) reactions on carbon, aluminum, iron, and lead targets at Q^{2}>1.5  (GeV/c)^{2}, x&#95;{B}>1.1 and missing momentum >400  MeV/c. This was the first direct measurement of both proton-proton (pp) and neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all measured nuclei, the average proton-proton (pp) to neutron-proton (np) reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for single-charge exchange effects decreased the SRC pairs ratio to ∼3%, which is lower than previous results. Comparisons to theoretical generalized contact formalism (GCF) cross-section calculations show good agreement using both phenomenological and chiral nucleon-nucleon potentials, favoring a lower pp to np pair ratio. The ability of the GCF calculation to describe the experimental data using either phenomenological or chiral potentials suggests possible reduction of scale and scheme dependence in cross-section ratios. Our results also support the high-resolution description of high-momentum states being predominantly due to nucleons in SRC pairs.

Published
2019
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40. First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N^{*} Resonance Region.

Author

Roy P, Park S, Crede V, Anisovich AV, Klempt E, Nikonov VA, Sarantsev AV, Wei NC, Huang F, Nakayama K, Adhikari KP, Adhikari S, Angelini G, Avakian H, Barion L, Battaglieri M, Bedlinskiy I, Biselli AS, Boiarinov S, Briscoe WJ, Brock J, Brooks WK, Burkert VD, Cao F, Carlin C, Carman DS, Celentano A, Chatagnon P, Chetry T, Ciullo G, Cole PL, Contalbrigo M, Cortes O, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Deur A, Diehl S, Djalali C, Dugger M, Dupre R, Duran B, Egiyan H, Ehrhart M, El Alaoui A, El Fassi L, Eugenio P, Fegan S, Filippi A, Fradi A, Gilfoyle GP, Girod FX, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guo L, Hafidi K, Hanretty C, Harrison N, Hattawy M, Hayward TB, Heddle D, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jenkins D, Jo HS, Johnston S, Joosten S, Kabir ML, Keith CD, Keller D, Khachatryan G, Khachatryan M, Khanal A, Khandaker M, Kim A, Kim W, Klein FJ, Kubarovsky V, Kuleshov SV, Kunkel MC, Lanza L, Lenisa P, Livingston K, MacGregor IJD, Marchand D, McKinnon B, Meekins DG, Meyer CA, Mineeva T, Mokeev V, Montgomery RA, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Paolone M, Pappalardo LL, Paremuzyan R, Pasyuk E, Payette D, Phelps W, Pierce J, Pogorelko O, Prok Y, Protopopescu D, Raue BA, Ripani M, Riser D, Ritchie BG, Rizzo A, Rosner G, Sabatié F, Salgado C, Schumacher RA, Seely ML, Sharabian YG, Shrestha U, Skorodumina I, Sokhan D, Soto O, Sparveris N, Strakovsky II, Strauch S, Taiuti M, Tan JA, Torayev B, Tyler N, Ungaro M, Voskanyan H, Voutier E, Walford NK, Wang R, Watts DP, Wei X, Wood MH, Zachariou N, Zhang J, and Zhao ZW

Abstract

First measurements of double-polarization observables in ω 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^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Published
2019
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41. Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the A(e,e^{'}pp) Reaction.

Author

Cohen EO, Hen O, Piasetzky E, Weinstein LB, Duer M, Schmidt A, Korover I, Hakobyan H, Adhikari S, Akbar Z, Amaryan MJ, Avakian H, Ball J, Barion L, Battaglieri M, Beck A, Bedlinskiy I, Biselli AS, Boiarinov S, Briscoe W, Burkert VD, Cao F, Carman DS, Celentano A, Charles G, Chatagnon P, Chetry T, Ciullo G, Clary BA, Contalbrigo M, Crede V, Cruz Torres R, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Defurne M, Deur A, Diehl S, Djalali C, Duer M, Dupre R, Egiyan H, Ehrhart M, El Alaoui A, Fassi LE, Eugenio P, Fedotov G, Fersch R, Filippi A, Ghandilyan Y, Giovanetti KL, Girod FX, Golovatch E, Gothe RW, Griffioen KA, Hafidi K, Harrison N, Hauenstein F, Heddle D, Hicks K, Holtrop M, Ireland DG, Ishkhanov BS, Isupov EL, Jenkins D, Jo HS, Johnston S, Kabir ML, Keller D, Khachatryan G, Khachatryan M, Khandaker M, Kim A, Kim W, Klein A, Klein FJ, Korover I, Kubarovsky V, Kuhn SE, Lanza L, Lenisa P, Livingston K, MacGregor IJD, Marchand D, McKinnon B, Mey-Tal Beck S, Meyer CA, Mirazita M, Mokeev V, Montgomery RA, Movsisyan A, Munoz Camacho C, Mustapha B, Nadel-Turonski P, Niccolai S, Niculescu G, Osipenko M, Ostrovidov AI, Paolone M, Paremuzyan R, Pasyuk E, Pogorelko O, Price JW, Prok Y, Protopopescu D, Ripani M, Riser D, Rizzo A, Rosner G, Rossi P, Sabatié F, Schmookler BA, Schumacher RA, Sharabian YG, Sokhan D, Sparveris N, Stepanyan S, Strauch S, Taiuti M, Tan JA, Ungaro M, Voskanyan H, Voutier E, Wang R, Watts DP, Wei X, Wood MH, Zachariou N, Zhang J, Zheng X, and Zhao ZW

Abstract

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k&#95;{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k&#95;{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170  MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.

Published
2018
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42. Measurement of the Q^{2} Dependence of the Deuteron Spin Structure Function g&#95;{1} and its Moments at Low Q^{2} with CLAS.

Author

Adhikari KP, Deur A, El Fassi L, Kang H, Kuhn SE, Ripani M, Slifer K, Zheng X, Adhikari S, Akbar Z, Amaryan MJ, Avakian H, Ball J, Balossino I, Barion L, Battaglieri M, Bedlinskiy I, Biselli AS, Bosted P, Briscoe WJ, Brock J, Bültmann S, Burkert VD, Thanh Cao F, Carlin C, Carman DS, Celentano A, Charles G, Chen JP, Chetry T, Choi S, Ciullo G, Clark L, Cole PL, Contalbrigo M, Crede V, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Defurne M, Djalali C, Dodge GE, Drozdov V, Dupre R, Egiyan H, El Alaoui A, Elouadrhiri L, Eugenio P, Fedotov G, Filippi A, Ghandilyan Y, Gilfoyle GP, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guler N, Guo L, Hafidi K, Hakobyan H, Hanretty C, Harrison N, Hattawy M, Heddle D, Hicks K, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Isupov EL, Jenkins D, Jo HS, Johnston SC, Joo K, Joosten S, Kabir ML, Keith CD, Keller D, Khachatryan G, Khachatryan M, Khandaker M, Kim W, Klein A, Klein FJ, Konczykowski P, Kovacs K, Kubarovsky V, Lanza L, Lenisa P, Livingston K, Long E, MacGregor IJD, Markov N, Mayer M, McKinnon B, Meekins DG, Meyer CA, Mineeva T, Mirazita M, Mokeev V, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Niculescu G, Niccolai S, Osipenko M, Ostrovidov AI, Paolone M, Pappalardo L, Paremuzyan R, Park K, Pasyuk E, Payette D, Phelps W, Phillips SK, Pierce J, Pogorelko O, Poudel J, Price JW, Prok Y, Protopopescu D, Raue BA, Rizzo A, Rosner G, Rossi P, Sabatié F, Salgado C, Schumacher RA, Sharabian YG, Shigeyuki T, Simonyan A, Skorodumina I, Smith GD, Sparveris N, Sokhan D, Stepanyan S, Strakovsky II, Strauch S, Sulkosky V, Taiuti M, Tan JA, Ungaro M, Voutier E, Wei X, Weinstein LB, Zhang J, and Zhao ZW

Abstract

We measured the g&#95;{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ&#95;{1}^{d} and the spin polarizability γ&#95;{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02  GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

Published
2018
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43. First Exclusive Measurement of Deeply Virtual Compton Scattering off ^{4}He: Toward the 3D Tomography of Nuclei.

Author

Hattawy M, Baltzell NA, Dupré R, Hafidi K, Stepanyan S, Bültmann S, De Vita R, El Alaoui A, El Fassi L, Egiyan H, Girod FX, Guidal M, Jenkins D, Liuti S, Perrin Y, Torayev B, Voutier E, Adhikari KP, Adhikari S, Adikaram D, Akbar Z, Amaryan MJ, Anefalos Pereira S, Armstrong WR, Avakian H, Ball J, Bashkanov M, Battaglieri M, Batourine V, Bedlinskiy I, Biselli AS, Boiarinov S, Briscoe WJ, Brooks WK, Burkert VD, Thanh Cao F, Carman DS, Celentano A, Charles G, Chetry T, Ciullo G, Clark L, Colaneri L, Cole PL, Contalbrigo M, Cortes O, Crede V, D'Angelo A, Dashyan N, De Sanctis E, Deur A, Djalali C, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Fersch R, Filippi A, Fleming JA, Forest TA, Fradi A, Garçon M, Gevorgyan N, Ghandilyan Y, Gilfoyle GP, Giovanetti KL, Gleason C, Gohn W, Golovatch E, Gothe RW, Griffioen KA, Guo L, Hakobyan H, Hanretty C, Harrison N, Heddle D, Hicks K, Holtrop M, Hughes SM, Ireland DG, Ishkhanov BS, Isupov EL, Jiang H, Joo K, Joosten S, Keller D, Khachatryan G, Khachatryan M, Khandaker M, Kim A, Kim W, Klein A, Klein FJ, Kubarovsky V, Kuhn SE, Kuleshov SV, Lanza L, Lenisa P, Livingston K, Lu HY, MacGregor IJD, Markov N, Mayer M, McCracken ME, McKinnon B, Meyer CA, Meziani ZE, Mineeva T, Mirazita M, Mokeev V, Montgomery RA, Moutarde H, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Net LA, Niccolai S, Niculescu G, Niculescu I, Osipenko M, Ostrovidov AI, Paolone M, Paremuzyan R, Park K, Pasyuk E, Phelps E, Phelps W, Pisano S, Pogorelko O, Price JW, Prok Y, Protopopescu D, Ripani M, Ritchie BG, Rizzo A, Rosner G, Rossi P, Sabatié F, Salgado C, Schumacher RA, Seder E, Sharabian YG, Simonyan A, Skorodumina I, Smith GD, Sokhan D, Sparveris N, Strauch S, Taiuti M, Ungaro M, Voskanyan H, Walford NK, Watts DP, Wei X, Weinstein LB, Wood MH, Zachariou N, Zana L, Zhang J, and Zhao ZW

Abstract

We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized ^{4}He gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling ^{4}He nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only ^{4}He Compton form factor, H&#95;{A}. This first measurement of coherent deeply virtual Compton scattering on the ^{4}He nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.

Published
2017
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44. Beam-Target Helicity Asymmetry for γ[over →]n[over →]→π^{-}p in the N^{*} Resonance Region.

Author

Ho D, Peng P, Bass C, Collins P, D'Angelo A, Deur A, Fleming J, Hanretty C, Kageya T, Khandaker M, Klein FJ, Klempt E, Laine V, Lowry MM, Lu H, Nepali C, Nikonov VA, O'Connell T, Sandorfi AM, Sarantsev AV, Schumacher RA, Strakovsky II, Švarc A, Walford NK, Wei X, Whisnant CS, Workman RL, Zonta I, Adhikari KP, Adikaram D, Akbar Z, Amaryan MJ, Anefalos Pereira S, Avakian H, Ball J, Bashkanov M, Battaglieri M, Batourine V, Bedlinskiy I, Biselli A, Briscoe WJ, Burkert VD, Carman DS, Celentano A, Charles G, Chetry T, Ciullo G, Clark L, Colaneri L, Cole PL, Contalbrigo M, Crede V, Dashyan N, De Sanctis E, De Vita R, Djalali C, Dupre R, El Alaoui A, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Fersch R, Filippi A, Fradi A, Ghandilyan Y, Gilfoyle GP, Girod FX, Glazier DI, Gleason C, Gohn W, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guo L, Hakobyan H, Harrison N, Hattawy M, Hicks K, Holtrop M, Hughes SM, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jenkins D, Jiang H, Jo HS, Joo K, Joosten S, Keller D, Khachatryan G, Kim A, Kim W, Klein A, Kubarovsky V, Kuleshov SV, Lanza L, Lenisa P, Livingston K, MacGregor IJD, Markov N, McKinnon B, Mineeva T, Mokeev V, Montgomery RA, Movsisyan A, Munoz Camacho C, Murdoch G, Niccolai S, Niculescu G, Osipenko M, Paolone M, Paremuzyan R, Park K, Pasyuk E, Phelps W, Pogorelko O, Price JW, Procureur S, Protopopescu D, Ripani M, Riser D, Ritchie BG, Rizzo A, Rosner G, Sabatié F, Salgado C, Sharabian YG, Skorodumina I, Smith GD, Sober DI, Sokhan D, Sparveris N, Strauch S, Tian Y, Torayev B, Ungaro M, Voskanyan H, Voutier E, Watts DP, Wood MH, Zachariou N, Zhang J, and Zhao ZW

Abstract

We report the first beam-target double-polarization asymmetries in the γ+n(p)→π^{-}+p(p) reaction spanning the nucleon resonance region from invariant mass W=1500 to 2300 MeV. Circularly polarized photons and longitudinally polarized deuterons in solid hydrogen deuteride (HD) have been used with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the E polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses and have led to significant revisions for several γnN^{*} resonance photocouplings.

Published
2017
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45. Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions.

Author

Jo HS, Girod FX, Avakian H, Burkert VD, Garçon M, Guidal M, Kubarovsky V, Niccolai S, Stoler P, Adhikari KP, Adikaram D, Amaryan MJ, Anderson MD, Anefalos Pereira S, Ball J, Baltzell NA, Battaglieri M, Batourine V, Bedlinskiy I, Biselli AS, Boiarinov S, Briscoe WJ, Brooks WK, Carman DS, Celentano A, Chandavar S, Charles G, Colaneri L, Cole PL, Compton N, Contalbrigo M, Crede V, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Deur A, Djalali C, Dupre R, Alaoui AE, Fassi LE, Elouadrhiri L, Fedotov G, Fegan S, Filippi A, Fleming JA, Garillon B, Gevorgyan N, Ghandilyan Y, Gilfoyle GP, Giovanetti KL, Goetz JT, Golovatch E, Gothe RW, Griffioen KA, Guegan B, Guler N, Guo L, Hafidi K, Hakobyan H, Harrison N, Hattawy M, Hicks K, Hirlinger Saylor N, Ho D, Holtrop M, Hughes SM, Ilieva Y, Ireland DG, Ishkhanov BS, Jenkins D, Joo K, Joosten S, Keller D, Khachatryan G, Khandaker M, Kim A, Kim W, Klein A, Klein FJ, Kuhn SE, Kuleshov SV, Lenisa P, Livingston K, Lu HY, MacGregor IJ, McKinnon B, Meziani ZE, Mirazita M, Mokeev V, Montgomery RA, Moutarde H, Movsisyan A, Munevar E, Munoz Camacho C, Nadel-Turonski P, Net LA, Niculescu G, Osipenko M, Ostrovidov AI, Paolone M, Park K, Pasyuk E, Phillips JJ, Pisano S, Pogorelko O, Price JW, Procureur S, Prok Y, Puckett AJ, Raue BA, Ripani M, Rizzo A, Rosner G, Rossi P, Roy P, Sabatié F, Salgado C, Schott D, Schumacher RA, Seder E, Simonyan A, Skorodumina Iu, Smith GD, Sokhan D, Sparveris N, Stepanyan S, Strakovsky II, Strauch S, Sytnik V, Tian Y, Tkachenko S, Ungaro M, Voskanyan H, Voutier E, Walford NK, Watts DP, Wei X, Weinstein LB, Wood MH, Zachariou N, Zana L, Zhang J, Zhao ZW, and Zonta I

Abstract

Unpolarized and beam-polarized fourfold cross sections (d^{4}σ/dQ^{2}dx&#95;{B}dtdϕ) for the ep→e^{'}p^{'}γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q^{2},x&#95;{B},t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction x&#95;{B}.

Published
2015
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46. Longitudinal target-spin asymmetries for deeply virtual compton scattering.

Author

Seder E, Biselli A, Pisano S, Niccolai S, Smith GD, Joo K, Adhikari K, Amaryan MJ, Anderson MD, Anefalos Pereira S, Avakian H, Battaglieri M, Bedlinskiy I, Bono J, Boiarinov S, Bosted P, Briscoe W, Brock J, Brooks WK, Bültmann S, Burkert VD, Carman DS, Carlin C, Celentano A, Chandavar S, Charles G, Colaneri L, Cole PL, Contalbrigo M, Crabb D, Crede V, D'Angelo A, Dashyan N, De Vita R, De Sanctis E, Deur A, Djalali C, Doughty D, Dupre R, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Filippi A, Fleming JA, Fradi A, Garillon B, Garçon M, Gevorgyan N, Ghandilyan Y, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Gothe RW, Griffioen KA, Guegan B, Guidal M, Guo L, Hafidi K, Hakobyan H, Hanretty C, Harrison N, Hattawy M, Hirlinger Saylor N, Holtrop M, Hughes SM, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jo HS, Joosten S, Keith CD, Keller D, Khachatryan G, Khandaker M, Kim A, Kim W, Klein A, Klein FJ, Koirala S, Kubarovsky V, Kuhn SE, Lenisa P, Livingston K, Lu HY, MacGregor IJ, Markov N, Mayer M, McKinnon B, Meekins DG, Mineeva T, Mirazita M, Mokeev V, Montgomery R, Moody CI, Moutarde H, Movsisyan A, Munoz Camacho C, Nadel-Turonski P, Niculescu I, Osipenko M, Ostrovidov AI, Paolone M, Pappalardo LL, Park K, Park S, Pasyuk E, Peng P, Phelps W, Pogorelko O, Price JW, Prok Y, Protopopescu D, Puckett AJ, Ripani M, Rizzo A, Rosner G, Rossi P, Roy P, Sabatié F, Salgado C, Schott D, Schumacher RA, Senderovich I, Simonyan A, Skorodumina I, Sokhan D, Sparveris N, Stepanyan S, Stoler P, Strakovsky II, Strauch S, Sytnik V, Taiuti M, Tang W, Tian Y, Ungaro M, Voskanyan H, Voutier E, Walford NK, Watts DP, Wei X, Weinstein LB, Wood MH, Zachariou N, Zana L, Zhang J, and Zonta I

Abstract

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x&#95;{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.

Published
2015
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47. Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment.

Author

Abrahamyan S, Ahmed Z, Allada K, Anez D, Averett T, Barbieri A, Bartlett K, Beacham J, Bono J, Boyce JR, Brindza P, Camsonne A, Cranmer K, Dalton MM, de Jager CW, Donaghy J, Essig R, Field C, Folts E, Gasparian A, Goeckner-Wald N, Gomez J, Graham M, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iqbal S, Jaros J, Jensen E, Kelleher A, Khandaker M, LeRose JJ, Lindgren R, Liyanage N, Long E, Mammei J, Markowitz P, Maruyama T, Maxwell V, Mayilyan S, McDonald J, Michaels R, Moffeit K, Nelyubin V, Odian A, Oriunno M, Partridge R, Paolone M, Piasetzky E, Pomerantz I, Qiang Y, Riordan S, Roblin Y, Sawatzky B, Schuster P, Segal J, Selvy L, Shahinyan A, Subedi R, Sulkosky V, Stepanyan S, Toro N, Walz D, Wojtsekhowski B, and Zhang J

Abstract

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

Published
2011
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48. Precise extraction of the induced polarization in the 4He(e,e'p)3H reaction.

Author

Malace SP, Paolone M, Strauch S, Albayrak I, Arrington J, Berman BL, Brash EJ, Briscoe B, Camsonne A, Chen JP, Christy ME, Chudakov E, Cisbani E, Craver B, Cusanno F, Ent R, Garibaldi F, Gilman R, Glamazdin O, Glister J, Higinbotham DW, Hyde-Wright CE, Ilieva Y, de Jager CW, Jiang X, Jones MK, Keppel CE, Khrosinkova E, Kuchina E, Kumbartzki G, Lee B, Lindgren R, Margaziotis DJ, Meekins D, Michaels R, Park K, Pentchev L, Perdrisat CF, Piasetzky E, Punjabi VA, Puckett AJ, Qian X, Qiang Y, Ransome RD, Saha A, Sarty AJ, Schulte E, Solvignon P, Subedi RR, Tang L, Tedeschi D, Tvaskis V, Udias JM, Ulmer PE, Vignote JR, Wesselmann FR, Wojtsekhowski B, and Zhan X

Abstract

We measured with unprecedented precision the induced polarization P(y) in (4)He(e,e'p)(3)H at Q(2)=0.8 and 1.3  (GeV/c)(2). The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are overestimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin-independent charge-exchange term in the latter calculation.

Published
2011
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49. Absorption of the ω and ϕ mesons in nuclei.

Author

Wood MH, Nasseripour R, Paolone M, Djalali C, Weygand DP, Adhikari KP, Anghinolfi M, Ball J, Battaglieri M, Batourine V, Bedlinskiy I, Bellis M, Berman BL, Biselli AS, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Careccia SL, Carman DS, Cole PL, Collins P, Crede V, D'Angelo A, Daniel A, De Vita R, De Sanctis E, Deur A, Dey B, Dhamija S, Dickson R, Doughty D, Dupre R, Egiyan H, El Alaoui A, El Fassi L, Eugenio P, Fegan S, Gabrielyan MY, Garçon M, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Gothe RW, Graham L, Guidal M, Guo L, Hafidi K, Hakobyan H, Hanretty C, Hassall N, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Jawalkar SS, Jo HS, Joo K, Keller D, Khandaker M, Khetarpal P, Kim A, Kim W, Klein A, Klein FJ, Konczykowski P, Kubarovsky V, Kuleshov SV, Kuznetsov V, Livingston K, Martinez D, Mayer M, McAndrew J, McCracken ME, McKinnon B, Meyer CA, Mineeva T, Mirazita M, Mokeev V, Moreno B, Moriya K, Morrison B, Munevar E, Nadel-Turonski P, Ni A, Niccolai S, Niculescu G, Niculescu I, Niroula MR, Osipenko M, Ostrovidov AI, Paremuzyan R, Park K, Park S, Pasyuk E, Anefalos Pereira S, Pisano S, Pogorelko O, Pozdniakov S, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Ripani M, Rosner G, Rossi P, Sabatié F, Saini MS, Salamanca J, Salgado C, Schott D, Schumacher RA, Seder E, Seraydaryan H, Sharabian YG, Smith GD, Sober DI, Sokhan D, Stepanyan S, Stepanyan SS, Stoler P, Strakovsky II, Strauch S, Taiuti M, Tang W, Taylor CE, Tedeschi DJ, Tkachenko S, Ungaro M, Vernarsky B, Vineyard MF, Voutier E, Watts DP, Weinstein LB, Zhang J, Zhao B, and Zhao ZW

Abstract

Because of their long lifetimes, the ω and ϕ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.

Published
2010
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50. Polarization transfer in the 4He(e,e'p)3H reaction at Q2=0.8 and 1.3 (GeV/c)2.

Author

Paolone M, Malace SP, Strauch S, Albayrak I, Arrington J, Berman BL, Brash EJ, Briscoe B, Camsonne A, Chen JP, Christy ME, Chudakov E, Cisbani E, Craver B, Cusanno F, Ent R, Garibaldi F, Gilman R, Glamazdin O, Glister J, Higinbotham DW, Hyde-Wright CE, Ilieva Y, de Jager CW, Jiang X, Jones MK, Keppel CE, Khrosinkova E, Kuchina E, Kumbartzki G, Lee B, Lindgren R, Margaziotis DJ, Meekins D, Michaels R, Park K, Pentchev L, Perdrisat CF, Piasetzky E, Punjabi VA, Puckett AJ, Qian X, Qiang Y, Ransome RD, Saha A, Sarty AJ, Schulte E, Solvignon P, Subedi RR, Tang L, Tedeschi D, Tvaskis V, Udias JM, Ulmer PE, Vignote JR, Wesselmann FR, Wojtsekhowski B, and Zhan X

Abstract

Proton recoil polarization was measured in the quasielastic 4He(e,e'p)3H reaction at Q{2}=0.8 and 1.3  (GeV/c){2} with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the 1H(e,e'p) reaction, contradicting a relativistic distorted-wave approximation and favoring either the inclusion of medium-modified proton form factors predicted by the quark-meson coupling model or a spin-dependent charge-exchange final-state interaction. For the first time, the polarization-transfer ratio is studied as a function of the virtuality of the proton.

Published
2010
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