Author: "EGIYAN, H." / Language: undetermined - Searchworks@Jio Institute Digital Library Search Results

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101 results on '"EGIYAN, H."'

1. Measurement of Spin-Density Matrix Elements in $ρ(770)$ Production with a Linearly Polarized Photon Beam at $E_γ= 8.2\,-\,8.8\,\text{GeV}$

Author: Adhikari, S., Afzal, F., Akondi, C. S., Albrecht, M., Amaryan, M., Arroyave, V., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Byer, D., Chudakov, E., Cole, P. L., Cortes, O., Crede, V., Dalton, M. M., Darulis, D., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Ebersole, D., Edo, M., Egiyan, H., Erbora, T., Eugenio, P., Fabrizi, A., Fanelli, C., Fang, S., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gardner, A., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Grube, B., Guo, J., Guo, L., Hague, T. J., Hakobyan, H., Hernandez, J., Hoffman, N. D., Hornidge, D., Hou, G., Huber, G. M., Hurck, P., Hurley, A., Imoehl, W., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jeske, T., Jones, R. T., Kakoyan, V., Kalicy, G., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Liu, B., Livingston, K., Lolos, G. J., Lorenti, L., Lyubovitskij, V., Ma, R., Mack, D., Mahmood, A., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Ng, L., Nissen, E., Orešić, S., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pedroni, R., Pentchev, L., Peters, K. J., Prather, E., Rakshit, S., Reinhold, J., Remington, A., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Saldana, K., Salgado, C., Schadmand, S., Schertz, A. M., Scheuer, K., Schick, A., Schmidt, A., Schumacher, R. A., Schwiening, J., Sharp, P., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, S., Somov, A., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Viducic, T., Whitlatch, T., Wickramaarachchi, N., Williams, M., Wunderlich, Y., Yu, B., Zarling, J., Zhang, Z., Zhao, Z., Zhou, X., Zhou, J., and Zihlmann, B.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract: The GlueX experiment at Jefferson Lab studies photoproduction of mesons using linearly polarized $8.5\,\text{GeV}$ photons impinging on a hydrogen target which is contained within a detector with near-complete coverage for charged and neutral particles. We present measurements of spin-density matrix elements for the photoproduction of the vector meson $ρ$(770). The statistical precision achieved exceeds that of previous experiments for polarized photoproduction in this energy range by orders of magnitude. We confirm a high degree of $s$-channel helicity conservation at small squared four-momentum transfer $t$ and are able to extract the $t$-dependence of natural and unnatural-parity exchange contributions to the production process in detail. We confirm the dominance of natural-parity exchange over the full $t$ range. We also find that helicity amplitudes in which the helicity of the incident photon and the photoproduced $ρ(770)$ differ by two units are negligible for $-t, 15 pages, 11 figures
Published: 2023
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2. Beam Spin Asymmetry Measurements of Deeply Virtual $π^0$ Production with CLAS12

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

Author: Adhikari, S., Afzal, F., Akondi, C. S., Albrecht, M., Amaryan, M., Arroyave, V., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Byer, D., Chudakov, E., Cole, P. L., Cortes, O., Crede, V., Dalton, M. M., Darulis, D., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Ebersole, D., Egiyan, H., Erbora, T., Eugenio, P., Fabrizi, A., Fanelli, C., Fang, S., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gardner, A., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Grube, B., Guo, J., Guo, L., Hague, T. J., Hakobyan, H., Hernandez, J., Hoffman, N. D., Hornidge, D., Hou, G., Huber, G. M., Hurck, P., Hurley, A., Imoehl, W., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jeske, T., Jones, R. T., Kakoyan, V., Kalicy, G., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Lorenti, L., Lyubovitskij, V., Mack, D., Mahmood, A., Martel, P. P., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Ng, L., Nissen, E., Orei, S., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pedroni, R., Pentchev, L., Peters, K. J., Prather, E., Rakshit, S., Reinhold, J., Remington, A., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Saldana, K., Salgado, C., Schadmand, S., Schertz, A. M., Scheuer, K., Schick, A., Schmidt, A., Schumacher, R. A., Schwiening, J., Sharp, P., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, S., Somov, A., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Viducic, T., Whitlatch, T., Wickramaarachchi, N., Williams, M., Wunderlich, Y., Yu, B., Zarling, J., Zhang, Z., Zhao, Z., Zhou, X., Zhou, J., and Zihlmann, B.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract: We report the total and differential cross sections for $J/ψ$ photoproduction with the large acceptance GlueX spectrometer for photon beam energies from the threshold at 8.2~GeV up to 11.44~GeV and over the full kinematic range of momentum transfer squared, $t$. Such coverage facilitates the extrapolation of the differential cross sections to the forward ($t = 0$) point beyond the physical region. The forward cross section is used by many theoretical models and plays an important role in understanding $J/ψ$ photoproduction and its relation to the $J/ψ-$proton interaction. These measurements of $J/ψ$ photoproduction near threshold are also crucial inputs to theoretical models that are used to study important aspects of the gluon structure of the proton, such as the gluon Generalized Parton Distribution (GPD) of the proton, the mass radius of the proton, and the trace anomaly contribution to the proton mass. We observe possible structures in the total cross section energy dependence and find evidence for contributions beyond gluon exchange in the differential cross section close to threshold, both of which are consistent with contributions from open-charm intermediate states., 15 pages 18 figures
Published: 2023
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4. Searching for Prompt and Long-Lived Dark Photons in Electro-Produced $e^+e^-$ Pairs with the Heavy Photon Search Experiment at JLab

Author: Adrian, P.H., Baltzell, N.A., Battaglieri, M., Bondí, M., Boyarinov, S., Bravo, C., Bueltmann, S., Butti, P., Burkert, V.D., Calvo, D., Cao, T., Carpinelli, M., Celentano, A., Charles, G., Colaneri, L., Cooper, W., Cuevas, C., d'Angelo, A., Dashyan, N., de Napoli, M., de Vita, R., Deur, A., Diamond, M., Dupre, R., Egiyan, H., Elouadrhiri, L., Essig, R., Fadeyev, V., Field, C., Filippi, A., Freyberger, A., Garçon, M., Gevorgyan, N., Girod, F.X., Graf, N., Graham, M., Griffioen, K.A., Grillo, A., Guidal, M., Herbst, R., Holtrop, M., Jaros, J., Johnson, R.P., Kalicy, G., Khandaker, M., Kubarovsky, V., Leonora, E., Livingston, K., Marsicano, L., Maruyama, T., Mccarty, S., Mccormick, J., Mckinnon, B., Moffeit, K., Moreno, O., Munoz Camacho, C., Nelson, T., Niccolai, S., Odian, A., Oriunno, M., Osipenko, M., Paremuzyan, R., Paul, S., Randazzo, N., Raydo, B., Reese, B., Rizzo, A., Schuster, P., Sharabian, Y.G., Simi, G., Simonyan, A., Sipala, V., Spellman, A., Sokhan, D., Solt, M., Stepanyan, S., Szumila-Vance, H., Toro, N., Uemura, S., Ungaro, M., Voskanyan, H., Weinstein, L.B., Wojtsekhowski, B., Yale, B., Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and HEP, INSPIRE
Subjects: photon: hidden sector, track data analysis: vertex, data analysis method, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], accelerator, engineering, HPS, FOS: Physical sciences, quantum electrodynamics: background, photon: electroproduction, High Energy Physics - Experiment, electron: pair production, phase space, High Energy Physics - Experiment (hep-ex), photon: mass, photon: heavy, mass spectrum: (electron positron), neutral particle: long-lived, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], mediation, coupling: (photon 2electron), upper limit, resonance: production, Jefferson Lab, experimental results
Abstract: The Heavy Photon Search experiment (HPS) at the Thomas Jefferson National Accelerator Facility searches for electro-produced dark photons. We report results from the 2016 Engineering Run consisting of 10608/nb of data for both the prompt and displaced vertex searches. A search for a prompt resonance in the $e^+e^-$ invariant mass distribution between 39 and 179 MeV showed no evidence of dark photons above the large QED background, limiting the coupling of {\epsilon}^2 {\geq} 10^-5, in agreement with previous searches. The search for displaced vertices showed no evidence of excess signal over background in the masses between 60 and 150 MeV, but had insufficient luminosity to limit canonical heavy photon production. This is the first displaced vertex search result published by HPS. HPS has taken high-luminosity data runs in 2019 and 2021 that will explore new dark photon phase space., Comment: 28 pages, 46 figures
Published: 2022
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5. A multidimensional study of the structure function ratio $σ_{LT'}/σ_{0}$ from hard exclusive $π^+$ electro-production off protons in the GPD regime

Author: Diehl, S., Kim, A., Joo, K., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avagyan, H., Gayoso, C. Ayerbe, Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossu, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Carman, D. S., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Grifoen, K. A., Guidal, M., Hafdi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Lagerquist, V., Laget, J. -M., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J. D., Marchand, D., Mascagna, V., McKinnon, B., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Molina, Esteban, Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Reed, Trevor, Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatie, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Spreafco, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences
Abstract: A multidimensional extraction of the structure function ratio $σ_{LT'}/σ_{0}$ from the hard exclusive $\vec{e} p \to e^\prime n π^+$ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime ($t/Q^{2}$ $\ll$ 1) with a wide kinematic range of $x_{B}$ in the valence regime (0.17 $, arXiv admin note: text overlap with arXiv:2007.15677
Published: 2022
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6. First CLAS12 measurement of DVCS beam-spin asymmetries in the extended valence region

Author: CLAS Collaboration, Christiaens, G., Defurne, M., Sokhan, D., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Cao, T., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holmberg, D. E., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Kabir, M. L., Keller, D., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J . D., Marchand, D., Mascagna, V., Matousek, G., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Molina, E., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Ramasubramanian, N., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Scott, M. B. C., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Ziegler, V., Zurek, M., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: electron p: deep inelastic scattering, interference: Bethe-Heitler, generalized parton distribution, nucleon: structure, parton: distribution function, FOS: Physical sciences, Newport News CEBAF Linac, momentum transfer dependence, photon: electroproduction, x-dependence, High Energy Physics - Experiment, error: statistical, phase space, High Energy Physics - Experiment (hep-ex), deeply virtual Compton scattering, beam: scattering, CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], spectrometer, +electron+p+photon%22">electron p --> electron p photon, electron: beam, valence, spin: asymmetry, experimental results
Abstract: Deeply virtual Compton scattering (DVCS) allows one to probe Generalized Parton Distributions (GPDs) describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarised protons. The results greatly extend the $Q^2$ and Bjorken-$x$ phase space beyond the existing data in the valence region and provide over 2000 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies., Comment: Revised Figure 4 and discussion around the number of effective ANNs after Bayesian reweighting
Published: 2022
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7. First Measurement of $Λ$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Author: Chetry, T., Fassi, L. El, Brooks, W. K., Dupré, R., Alaoui, A. El, Hafidi, K., Achenbach, P., Adhikari, K. P., Akbar, Z., Armstrong, W. R., Arratia, M., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Kabir, M. L., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I. J. D., Marchand, D., Mascagna, V., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rosner, G., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Weinstein, L. B., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex)
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., 14 pages, 6 figures
Published: 2022
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8. 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, K. P., Armstrong, W. R., Atac, H., Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, Louise, Cole, P. L., 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, F. X., Glazier, Derek I., Golubenko, A., Gothe, R. W., Griffioen, K., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, David G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Korover, I., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, Kenneth, MacGregor, I. J. Douglas, Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, Bryan, McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munevar, E., Munoz Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O’Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Pogorelko, O., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, Guenther, Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, Daria, Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyson, Richard, Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wishart, Robert, Wood, M. H., Yale, B., Yurov, M., Zhang, J., and Zhao, Z. W.
Subjects: Hyperons in neutron stars, Economica, PE2_2, PE2_1, Settore FIS/04, Nuclear Theory, Socio-culturale, Ambientale, ddc:530, Hyperons's Scattering, Nuclear Experiment, PE2_3
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 \ud Λ\ud −\ud N\ud scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the \ud Λ\ud p\ud →\ud Λ\ud p\ud elastic scattering cross section in the incident \ud Λ\ud momentum range \ud 0.9\ud –\ud 2.0\ud \ud \ud GeV\ud /\ud c\ud . 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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9. Observation of Beam Spin Asymmetries in the Process ep→e^{'}π^{+}π^{-}X with CLAS12

Author: Hayward, T B, Dilks, C, Vossen, A, Avakian, H, Adhikari, S, Angelini, G, Arratia, M, Atac, H, Ayerbe Gayoso, C, Baltzell, N A, Barion, L, Battaglieri, M, Bedlinskiy, I, Benmokhtar, F, Bianconi, A, Biselli, A S, Bondì, M, Bossù, F, Boiarinov, S, Briscoe, W J, Brooks, W K, Bulumulla, D, Burkert, V D, Carman, D S, Carvajal, J C, Celentano, A, Chatagnon, P, Chetry, T, Ciullo, G, Clary, B A, Cole, P L, Contalbrigo, M, Costantini, G, Crede, V, D'Angelo, A, Dashyan, N, De Vita, R, Defurne, M, Deur, A, Diehl, S, Djalali, C, Dupre, R, Dugger, M, Egiyan, H, Ehrhart, M, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Fegan, S, Filippi, A, Forest, T A, Gavalian, G, Gilfoyle, G P, Girod, F X, Glazier, Derek I., Golubenko, A A, Gothe, R W, Gotra, Y, Griffioen, K A, Guidal, M, Hafidi, K, Hakobyan, H, Hattawy, M, Hauenstein, F, Hicks, K, Hobart, A, Holtrop, M, Ireland, David G., Isupov, E L, Jo, H S, Joo, K, Joosten, S, Keller, D, Khachatryan, M, Khanal, A, Kim, A, Kim, W, Kripko, A, Kubarovsky, V, Kuhn, S E, Lanza, L, Leali, M, Lee, S, Lenisa, P, Livingston, Kenneth, MacGregor, I.D. Douglas, Marchand, D, Markov, N, Marsicano, L, Mascagna, V, McKinnon, Bryan, Meziani, Z E, Mirazita, M, Mokeev, V, Movsisyan, A, Munoz Camacho, C, Nadel-Turonski, P, Naidoo, Paul, Nanda, S, Neupane, K, Niccolai, S, Niculescu, G, O'Connell, T R, Osipenko, M, Paolone, M, Pappalardo, L L, Paremuzyan, R, Pasyuk, E, Phelps, W, Pogorelko, O, Prok, Y, Raue, B A, Ripani, M, Ritman, J, Rizzo, A, Rossi, P, Rowley, J, Sabatié, F, Salgado, C, Schmidt, A, Segarra, E P, Sharabian, Y G, Shrestha, U, Sokhan, Daria, Soto, O, Sparveris, N, Stepanyan, S, Strakovsky, I I, Strauch, S, Thornton, Adam, Tyler, N, Tyson, Richard, Ungaro, M, Venturelli, L, Voskanyan, H, Voutier, E, Watts, D P, Wei, K, Wei, X, Wood, M H, Yale, B, Zachariou, N, Zhang, J, and College of William and Mary [Williamsburg] (WM)
Subjects: [PHYS]Physics [physics], Parton Distribution Functions, Physics, Settore FIS/04, Nuclear Theory, NO, PE2_2, Quantum Chomodynamics, PE2_1, Quarks and Gluons, Physics::Accelerator Physics, High Energy Physics::Experiment, ddc:530, Nuclear Experiment, PE2_3, ComputingMilieux_MISCELLANEOUS
Abstract: The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G_{1}^{⊥}. 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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10. Observation of Beam Spin Asymmetries in the Process $e p \rightarrow e ��^{+}��^{-}X$ with CLAS12

Author: Hayward, T. B., Dilks, C., Vossen, A., Avakian, H., Adhikari, S., Angelini, G., Arratia, M., Atac, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bond��, M., Boss��, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T. A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hicks, K., Hobart, A., Holtrop, M., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Nanda, S., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Rowley, J., Sabati��, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., and Zhang, J.
Subjects: High Energy Physics - Experiment (hep-ex), Nuclear Theory, Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract: The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function $e(x)$, which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function $G_1^\perp$. A clear sign change is observed around the $��$ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark., 6 pages, 5 figures
Published: 2021
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11. Measurement of deeply virtual Compton scattering off Helium-4 with CLAS at Jefferson Lab

Author: DUPRÉ, R., HATTAWY, M., BALTZELL, N.A., BÜLTMANN, S., DE VITA, R., EL ALAOUI, A., EL FASSI, L., EGIYAN, H., GIROD, F.X., GUIDAL, M., HAFIDI, K., JENKINS, D., LIUTI, S., PERRIN, Y., STEPANYAN, S., TORAYEV, B., VOUTIER, E., AMARYAN, M.J., ARMSTRONG, W.R., ATAC, H., GAYOSO, C. Ayerbe, BARION, L., BATTAGLIERI, M., BEDLINSKIY, I., BENMOKHTAR, F., BIANCONI, A., BISELLI, A.S., BONDI, M., BOSSÙ, F., BOIARINOV, S., BRISCOE, W.J., BULUMULLA, D., BURKERT, V., CARMAN, D.S., CARVAJAL, J.C., CAUDRON, M., CELENTANO, A., CHATAGNON, P., CHESNOKOV, V., CHETRY, T., CIULLO, G., CLARY, B.A., COLE, P.L., CONTALBRIGO, M., COSTANTINI, G., CREDE, V., D'ANGELO, A., DASHYAN, N., DEFURNE, M., DEUR, A., DIEHL, S., DJALALI, C., EHRHART, M., ELOUADRHIRI, L., EUGENIO, P., FEGAN, S., FILIPPI, A., FOREST, T.A., GHANDILYAN, Y., GILFOYLE, G.P., GOTHE, R.W., GRIFFIOEN, K.A., HAKOBYAN, H., HAYWARD, T.B., HICKS, K., HOBART, A., HOLTROP, M., ILIEVA, Y., IRELAND, D.G., ISUPOV, E.L., JO, H.S., JOO, K., JOOSTEN, S., KELLER, D., KHACHATRYAN, G., KHANAL, A., KHANDAKER, M., KIM, A., KIM, W., KRIPKO, A., KUBAROVSKY, V., KUHN, S.E., LANZA, L., LIVINGSTON, K., KABIR, M.L., LEALI, M., LENISA, P., MACGREGOR, I.J.D., MARCHAND, D., MARKOV, N., MASCAGNA, V., MAYER, M., MCKINNON, B., MIRAZITA, M., MOKEEV, V.I., NEUPANE, K., NICCOLAI, S., O'CONNELL, T.R., OSIPENKO, M., PAOLONE, M., PAPPALARDO, L.L., PAREMUZYAN, R., PASYUK, E., PAYETTE, D., PHELPS, W., PIVNYUK, N., POGORELKO, O., POUDEL, J., PROK, Y., RIPANI, M., RITMAN, J., RIZZO, A., ROSNER, G., ROSSI, P., ROWLEY, J., SABATIÉ, F., SALGADO, C., SCHMIDT, A., SCHUMACHER, R., SERGEYEVA, V., SHARABIAN, Y., SHRESTHA, U., SOKHAN, D., SOTO, O., SPARVERIS, N., STRAKOVSKY, I.I., STRAUCH, S., TYLER, N., UNGARO, M., VENTURELLI, L., VOSKANYAN, H., VOSSEN, A., WATTS, D., WEI, K., WEI, X., WEINSTEIN, L.B., WISHART, R., WOOD, M.H., YALE, B., ZACHARIOU, N., and ZHANG, J.
Subjects: Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off $^4$He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized $^4$He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling $^4$He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the coherent ($e^4$He$~\to~e'$$^4$He$'\gamma'$) beam spin asymmetries compared to those observed on the free proton, while the incoherent ($e^4$He$~\to~e'$p$'\gamma'$X$'$) asymmetries exhibit a 30$\%$ suppression. From the coherent data, we were able to extract, in a model-independent way, the real and imaginary parts of the only $^4$He Compton form factor, $\cal H_A$, leading the way toward 3D imaging of the partonic structure of nuclei.
Published: 2021
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12. Improved $��p$ Elastic Scattering Cross Sections Between 0.9 and 2.0 GeV/c and Connections to the Neutron Star Equation of State

Author: CLAS Collaboration, Rowley, J., Compton, N., Djalali, C., Hicks, K., Price, J., Zachariou, N., Adhikari, K. P., Armstrong, W. R., Atac, H., Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Gavalian, G., Girod, F. X., Glazier, D. I., Golubenko, A., Gothe, R. W., Griffioen, K., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Korover, I., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Pogorelko, O., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wishart, R., Wood, M. H., Yale, B., Yurov, M., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment (hep-ex), Nuclear Theory, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state (EOS). Yet, compared to other elastic scattering processes, there is very little data on $��$-$N$ scattering. This experiment utilized the CLAS detector to study the $��p \rightarrow ��p$ elastic scattering cross section in the incident $��$ momentum range 0.9-2.0 GeV/c. This is the first data on this reaction in several decades. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments., 6 pages, 5 figures
Published: 2021
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13. Polarized Structure Function $��_{LT'}$ from $��^0 p$ Electroproduction Data in the Resonance Region at $0.4$ GeV$^2 < Q^2 < 1.0$ GeV$^2$

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., Boss��, 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., Alaoui, A. El, Fassi, L. El, 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., Camacho, C. Munoz, 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., Sabati��, 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: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The first results on the $��_{LT'}$ structure function in exclusive $��^0p$ electroproduction at invariant masses of the final state of 1.5 GeV $, 7 pages, 3 figures
Published: 2021
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14. Observation of Beam Spin Asymmetries in the Process ep→e′π+π−X with CLAS12

Author: Hayward, T. B., Dilks, C., Vossen, A., Avakian, H., Adhikari, S., Angelini, G., Arratia, M., Atac, H., Ayerbe Gayoso, C., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondì, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T. A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hicks, K., Hobart, A., Holtrop, M., Ireland, D. G., Isupov, E. L., H. S., Jo, Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., Macgregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., Mckinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Movsisyan, A., Munoz Camacho, C., Nadel-Turonski, P., Naidoo, P., Nanda, S., Neupane, K., Niccolai, S., Niculescu, G., O’Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., 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 G1⊥. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark.
Published: 2021

15. Beam-spin asymmetry Σ for Σ− hyperon photoproduction off the neutron

Author: Zachariou, N., Munevar, E., Berman, B.L., Bydžovský, P., Cieplý, A., Feldman, G., Ilieva, Y., Nadel-Turonski, P., Skoupil, D., Sarantsev, A.V., Watts, D.P., Amaryan, M.J., Angelini, G., Armstrong, W.R., Atac, H., Avakian, H., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A.S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Bulumulla, D., Burkert, V.D., Carman, D.S., Carvajal, J.C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, Louise, Cole, P.L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fradi, A., Gavalian, G., Gilfoyle, G.P., Girod, F.X., Gleason, C., Golubenko, A.A., Gothe, R.W., Griffioen, K.A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T.B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ireland, D.G., Isupov, E.L., Jenkins, D., Jo, H.S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Klein, F.J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Livingston, K., MacGregor, I.D.G., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munoz Camacho, C., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T.R., Osipenko, M., Ostrovidov, A.I., Pandey, P., Paolone, M., Pappalardo, L.L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J.W., Prok, Y., Raue, B.A., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R.A., Sharabian, Y.G., Shirokov, E.V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I.I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Wei, K., Wei, X., Wishart, R., Wood, M.H., Yale, B., Zhang, J., and Zhao, Z.W.
Subjects: Nuclear and High Energy Physics, ddc:530
Abstract: Physics letters / B 827, 136985 (2022). doi:10.1016/j.physletb.2022.136985, Published by North-Holland Publ., Amsterdam
Published: 2022
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16. Probing the core of the strong nuclear interaction

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

Author: Diehl, S., Joo, K., Kim, A., Avakian, H., Kroll, P., Park, K., Riser, D., Semenov-Tian-Shansky, K., Tezgin, K., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boss`u, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, G., Osipenko, M., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Raue, B. A., Ripani, M., Rizzo, A., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We have measured beam-spin asymmetries to extract the $\sin��$ moment $A_{LU}^{\sin��}$ from the hard exclusive $\vec{e} p \to e^\prime n ��^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin��}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin��}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.
Published: 2020
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18. Studying Short-Range Correlations with Real Photon Beams at GlueX

Author: Hen, O., Patsyuk, M., Piasetzky, E., Schmidt, A., Somov, A., Szumila-Vance, H., Weinstein, L. B., Dutta, D., Gao, H., Amaryan, M., Ashkenazi, A., Beck, A., Berdnikov, V., Black, T., Briscoe, W. J., Britton, T., Brooks, W., Cruz-Torres, R., Dalton, M. M., Denniston, A., Deur, A., Egiyan, H., Fanelli, C., Fegan, S., Furletov, S., Gan, L., Guo, L., Hauenstein, F., Haykobyan, H., Higinbotham, D. W., Ireland, D. G., Johansson, G., Kamel, M., Korover, I., Kuleshov, S., Lawrence, D., Livingston, K., Mack, D., Marukyan, H., McCaughan, M., Mckinnon, B., Meytal-Beck, S., Nerline, F., Nguyen, D., Papadopoulou, A., Pauli, P., Pedroni, R., Pentchev, L., Pybus, J. R., Ratliff, S., Romanov, D., Romera, C., Salgado, C., Schmookler, B., Segarra, E. P., Seroka, E., Sharp, P., Somov, S., Strakovsky, I. I., Taylor, S., Thiel, A., and Zihlmann, B.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The past few years has seen tremendous progress in our understanding of short-range correlated (SRC) pairing of nucleons within nuclei, much of it coming from electron scattering experiments leading to the break-up of an SRC pair. The interpretation of these experiments rests on assumptions about the mechanism of the reaction. These assumptions can be directly tested by studying SRC pairs using alternate probes, such as real photons. We propose a 30-day experiment using the Hall D photon beam, nuclear targets, and the GlueX detector in its standard configuration to study short-range correlations with photon-induced reactions. Several different reaction channels are possible, and we project sensitivity in most channels to equal or exceed the 6 GeV-era SRC experiments from Halls A and B. The proposed experiment will therefore decisively test the phenomena of np dominance, the short-distance NN interaction, and reaction theory, while also providing new insight into bound nucleon structure and the onset of color transparency., Comment: 38 pages, 26 figures, proposal for Jefferson Lab Experiment E12-19-003, submitted to Jefferson Lab PAC 47 (2019)
Published: 2020
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19. Measurement of beam asymmetry for $��^-��^{++}$ photoproduction on the proton at $E_��$=8.5 GeV

Author: GlueX Collaboration, Adhikari, S., Akondi, C. S., Ali, A., Amaryan, M., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., Kuleshov, S., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Luckas, K., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Reinhold, J., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Romero, C., Salgado, C., Schadmand, S., Schertz, A. M., Schick, A., Schumacher, R. A., Schwiening, J., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Yang, Y., Zarling, J., Zhang, Z., Zhao, Z., Zhou, J., Zhou, Q., Zhou, X., and Zihlmann, B.
Subjects: High Energy Physics - Experiment (hep-ex), Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report a measurement of the $��^-$ photoproduction beam asymmetry for the reaction $\vec�� p \rightarrow ��^- ��^{++}$ using data from the GlueX experiment in the photon beam energy range 8.2--8.8 GeV. The asymmetry $��$ is measured as a function of four-momentum transfer $t$ to the $��^{++}$ and compared to phenomenological models. We find that $��$ varies as a function of $t$: negative at smaller values and positive at higher values of $|t|$. The reaction can be described theoretically by $t$-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy., 7 pages, 5 figures
Published: 2020
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20. Measurement of the Photon Beam Asymmetry in $\vec�� p\to K^+��^0$ at $E_�� = 8.5$ GeV

Author: The GlueX Collaboration, Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ni, H., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhou, Q., Zhou, X., and Zihlmann, B.
Subjects: High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report measurements of the photon beam asymmetry $��$ for the reaction $\vec�� p\to K^+��^0$(1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected using a linearly polarized photon beam in the energy range of 8.2-8.8 GeV incident on a liquid hydrogen target. The beam asymmetry $��$ was measured as a function of the Mandelstam variable $t$, and a single value of $��$ was extracted for events produced in the $u$-channel. These are the first exclusive measurements of the photon beam asymmetry $��$ for the reaction in this energy range. For the $t$-channel, the measured beam asymmetry is close to unity over the $t$-range studied, $-t=(0.1-1.4)~$(GeV/$c$)$^{2}$, with an average value of $��= 1.00\pm 0.05$. This agrees with theoretical models that describe the reaction via the natural-parity exchange of the $K^{*}$(892) Regge trajectory. A value of $��= 0.41 \pm 0.09$ is obtained for the $u$-channel integrated up to $-u=2.0$~(GeV/$c$)$^{2}$.
Published: 2020
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21. First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton

Author: The GlueX Collaboration, Ali, A., Amaryan, M., Anassontzis, E. G., Austregesilo, A., Baalouch, M., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gauzshtein, V., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Han, S., Hardin, J., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Kuznetsov, I., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Werthmueller, D., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.
Subjects: Physics, Scattering cross-section, GlueX, General Physics and Astronomy, Exotic hadron, 01 natural sciences, 7. Clean energy, Pentaquark, Model exchange, Nuclear physics, Near threshold, 0103 physical sciences, High Energy Physics::Experiment, Photon beam, 010306 general physics, Nuclear Experiment
Abstract: We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\sigma /dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/\psi p)$ and cross sections $\sigma(\gamma p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/\psi p) $., Comment: 12 pages, 7 figures
Published: 2019

22. First measurement of near-threshold J/$��$ exclusive photoproduction off the proton

Author: The GlueX Collaboration, Ali, A., Amaryan, M., Anassontzis, E. G., Austregesilo, A., Baalouch, M., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gauzshtein, V., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Han, S., Hardin, J., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Kuznetsov, I., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Werthmueller, D., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.
Subjects: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report on the measurement of the $��p \rightarrow J/��p$ cross section from $E_��= 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d��/dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/��p)$ and cross sections $��(��p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/��p) $., 12 pages, 7 figures
Published: 2019
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23. Beam Asymmetry $\mathbf��$ for the Photoproduction of $\mathbf��$ and $\mathbf{��^{\prime}}$ Mesons at $\mathbf{E_��=8.8}$GeV

Author: The GlueX Collaboration, Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Mattione, P., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Staib, M., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report on the measurement of the beam asymmetry $��$ for the reactions $\vec��p\rightarrow p��$ and $\vec��p \rightarrow p��^{\prime}$ from the GlueX experiment, using an 8.2--8.8 GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Lab. These measurements are made as a function of momentum transfer $-t$, with significantly higher statistical precision than our earlier $��$ measurements, and are the first measurements of $��^{\prime}$ in this energy range. We compare the results to theoretical predictions based on $t$--channel quasi-particle exchange. We also compare the ratio of $��_��$ to $��_{��^{\prime}}$ to these models, as this ratio is predicted to be sensitive to the amount of $s\bar{s}$ exchange in the production. We find that photoproduction of both $��$ and $��^{\prime}$ is dominated by natural parity exchange with little dependence on $-t$., 18 pages, 7 figures
Published: 2019
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24. 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, P., Chetry, T., Ciullo, G., Clary, B. 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, M., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Hafidi, K., Harrison, N., Hauenstein, F., Heddle, D., Hicks, K., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., H. S., Jo, 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., Sabatie, 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: trasparency, Physics and Astronomy (all), proton propagation, High Q(2), Socio-culturale, momentum, High Q(2), momentum, energy, trasparency, proton propagation, spectral function, spectral function, energy, Settore FIS/04 - Fisica Nucleare e Subnucleare
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

25. Beam-Target Helicity Asymmetry $E$ in $K^{0}��$ and $K^{0}��^0$ Photoproduction on the Neutron

Author: CLAS Collaboration, Ho, D. H., Schumacher, R. A., D'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Klein, F. J., Klempt, E., Lowry, M. M., Lu, H., Nikonov, V. A., Peng, P., Sandorfi, A. M., Sarantsev, A. V., Strakovsky, I. I., Walford, N. K., Wei, X., Workman, R. L., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Ball, J., Barion, L., Bashkanov, M., Bass, C. D., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Boiarinov, S., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P., Contalbrigo, M., Crede, V., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Laine, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Markov, N., Mayer, M., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Rehfuss, M., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabati��, 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 Theory, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report the first measurements of the $E$ beam-target helicity asymmetry for the $\vec�� \vec{n} \to K^{0}��$, and $K^{0}��^{0}$ channels in the energy range 1.70$\leq W\leq$2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees was used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin $I=0$ and $I=1$ photo-coupling transition amplitudes in pseudoscalar meson photoproduction., 14 pages, 9 figures; Revised to match published version
Published: 2018
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26. First Measurements of the Double-Polarization Observables $F$, $P$, and $H$ in $��$ Photoproduction off Transversely Polarized Protons in the $N^\ast$ Resonance Region

Author: Roy, P., Park, S., Crede, V., Anisovich, A. V., Klempt, E., Nikonov, V. A., Sarantsev, A. V., Wei, N. C., Huang, F., Nakayama, K., Adhikari, K. P., Adhikari, S., Angelini, G., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Burkert, V. D., Cao, F., Carlin, C., Carman, D. S., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Duran, B., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fegan, S., Filippi, A., Fradi, A., Gilfoyle, G. P., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joosten, S., Kabir, M. L., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Kunkel, M. C., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., McKinnon, B., Meekins, D. G., Meyer, C. A., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Payette, D., Phelps, W., Pierce, J., Pogorelko, O., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Torayev, B., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment (hep-ex), Nuclear Theory, Physics::Accelerator Physics, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: First measurements of double-polarization observables in $��$ photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry $F$ has been measured using circularly polarized, tagged photons in the energy range 1200 - 2700 MeV, and the beam-target asymmetries $H$ and $P$ have been measured using linearly polarized tagged photons in the energy range 1200 - 2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon ($N^\ast$) resonances. In particular, contributions from new $N^\ast$ resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum., Two authors added, figures updated
Published: 2018
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27. First results on nucleon resonance photocouplings from the $��p \to ��^+��^-p$ reaction

Author: CLAS Collaboration, Golovatch, E., Burkert, V. D., Carman, D. S., Gothe, R. W., Hicks, K., Ishkhanov, B. S., Mokeev, V. I., Pasyuk, E., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Cao, F., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., McKinnon, B., Meyer, C. A., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabati��, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the $��p \to ��^+��^-p$ reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6~GeV~$
Published: 2018
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28. Measurement of two-photon exchange effect by comparing elastic e±p cross sections

Author: Rimal, D, Adikaram, D, Raue, BA, Weinstein, LB, Arrington, J, Brooks, WK, Ungaro, M, Adhikari, KP, Afanasev, AV, Akbar, Z, Pereira, S Anefalos, Badui, RA, Ball, J, Baltzell, NA, Battaglieri, M, Batourine, V, Bedlinskiy, I, Biselli, AS, Boiarinov, S, Briscoe, WJ, Bültmann, S, Burkert, VD, Carman, DS, Celentano, A, Chetry, T, Ciullo, G, Clark, L, Colaneri, L, Cole, PL, Compton, N, Contalbrigo, M, Cortes, O, Crede, V, D'Angelo, A, Dashyan, N, De Vita, R, Deur, A, Djalali, C, Dupre, R, Egiyan, H, Alaoui, A El, Fassi, L El, Eugenio, P, Fanchini, E, Fedotov, G, Fersch, R, Filippi, A, Fleming, JA, Forest, TA, Fradi, A, Gevorgyan, N, Ghandilyan, Y, Gilfoyle, GP, Giovanetti, KL, Girod, FX, Gleason, C, Gohn, W, Golovatch, E, Gothe, RW, Griffioen, KA, Guo, L, Hafidi, K, Hanretty, C, Harrison, N, Hattawy, M, Heddle, D, Hicks, K, Holtrop, M, Hughes, SM, Ilieva, Y, Ireland, DG, Ishkhanov, BS, Isupov, EL, Jenkins, D, Jiang, H, Joosten, S, Keller, D, Khachatryan, G, Khandaker, M, Kim, W, Klein, A, Klein, FJ, Kubarovsky, V, Kuhn, SE, Kuleshov, SV, Lanza, L, Lenisa, P, Livingston, K, Lu, HY, MacGregor, IJD, Markov, N, McKinnon, B, Mestayer, MD, Mirazita, M, Mokeev, V, Movsisyan, A, Munevar, E, Camacho, C Munoz, Nadel-Turonski, P, and Ni, A
Subjects: Particle and Plasma Physics, Molecular, Physics::Accelerator Physics, Nuclear, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles Physics
Abstract: Background: The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four-momentum transfer (Q2). Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed. Purpose: We measured the ratio of positron-proton to electron-proton elastic-scattering cross sections in order to determine the TPE contribution to elastic electron-proton scattering and thereby resolve the proton electric form factor discrepancy. Methods: We produced a mixed simultaneous electron-positron beam in Jefferson Lab's Hall B by passing the 5.6-GeV primary electron beam through a radiator to produce a bremsstrahlung photon beam and then passing the photon beam through a convertor to produce electron-positron pairs. The mixed electron-positron (lepton) beam with useful energies from approximately 0.85 to 3.5 GeV then struck a 30-cm-long liquid hydrogen (LH2) target located within the CEBAF Large Acceptance Spectrometer (CLAS). By detecting both the scattered leptons and the recoiling protons, we identified and reconstructed elastic scattering events and determined the incident lepton energy. A detailed description of the experiment is presented. Results: We present previously unpublished results for the quantity R2γ, the TPE correction to the elastic-scattering cross section, at Q2≈0.85 and 1.45 GeV2 over a large range of virtual photon polarization ?. Conclusions: Our results, along with recently published results from VEPP-3, demonstrate a nonzero contribution from TPE effects and are in excellent agreement with the calculations that include TPE effects and largely reconcile the form-factor discrepancy up to Q2≈2GeV2. These data are consistent with an increase in R2γ with decreasing ? at Q2≈0.85 and 1.45 GeV2. There are indications of a slight increase in R2γ with Q2.
Published: 2017

29. Differential Cross Section Measurements for $��n\to��^-p$ 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., Pereira, S. Anefalos, 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., Alaoui, A. El, Fassi, L. El, 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, Camacho, C. Munoz, 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., Sabati��, 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: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The quasi-free $��d\to��^{-}p(p)$ differential cross section has been measured with CLAS at photon beam energies $E_��$ from 0.445 GeV to 2.510 GeV (corresponding to $W$ from 1.311 GeV to 2.366 GeV) for pion center-of-mass angles $\cos��_��^{c.m.}$ from -0.72 to 0.92. A correction for final state interactions has been applied to this data to extract the $��n\to��^-p$ differential cross sections. These cross sections are quoted in 8428 $(E_��,\cos��_��^{c.m.})$ bins, a factor of nearly three increase in the world statistics for this channel in this kinematic range. These new data help to constrain coupled-channel analysis fits used to disentangle the spectrum of $N^*$ resonances and extract their properties. Selected photon decay amplitudes $N^* \to ��n$ at the resonance poles are determined for the first time and are reported here.
Published: 2017
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30. Photon beam asymmetry $��$ in the reaction $\vec�� p \to p ��$ for $E_��$ = 1.152 to 1.876 GeV

Author: CLAS Collaboration, Collins, P., Ritchie, B. G., Dugger, M., Klein, F. J., Anisovich, A. V., Klempt, E., Nikonov, V. A., Sarantsev, A., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, Frank Thanh, Cao, T., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Filippi, A., Fleming, J. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Photon beam asymmetry $��$ measurements for $��$ photoproduction in the reaction $\vec�� p \to ��p$ are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between $t$-channel meson exchange and $s$- and $u$-channel contributions, underscoring sensitivity to the nucleon resonances included in those descriptions. Comparisons with the Bonn-Gatchina partial-wave analysis indicate the $��$ data reported here help to fix the magnitudes of the interference terms between the leading amplitudes in that calculation (Pomeron exchange and the resonant portion of the $J^P=3/2^+$ partial wave), as well as the resonant portions of the smaller partial waves with $J^P$= $1/2^-$, $3/2^-$, and $5/2^+$., 10 pages, 3 figures
Published: 2017
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31. Measurement of the beam asymmetry Σ for π0 and η photoproduction on the proton at Eγ=9 GeV

Author: Al Ghoul, H., Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barnes, A., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Brooks, W. K., Cannon, B. E., Chernyshov, O., Chudakov, E., Crede, V., Dalton, M. M., Deur, A., Dobbs, S., Dolgolenko, A., Dugger, M., Dzhygadlo, R., Egiyan, H., Eugenio, P., Fanelli, C., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Goetzen, K., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kamel, M., Klein, F. J., Kliemt, R., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Lara, M., Larin, I., Lawrence, D., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Mendez, R., Meyer, Curtis, Miskimen, R., Mitchell, R. E., Mokaya, F., Moriya, K., Nerling, F., Nigmatkulov, G., Ochoa, N., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pedroni, R., Pennington, M. R., Pentchev, L, Peters, K. J., Pooser, E., Pratt, B., Qiang, Y., Reinhold, J., Ritchie, B. G., Robison, L, Romanov, D., Salgado, C., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Tarasov, V., Taylor, S., Teymurazyan, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Vasileiadis, G., Vega, I, Walford, N. K., Werthmuller, D., Whitlatch, T., Williams, M., Wolin, E., Xiao, T., Zarling, J., Zhang, Z., and Zihlmann, B.
Subjects: FOS: Physical sciences, Nuclear Experiment, 20202 Nuclear Physics, 20203 Particle Physics
Abstract: We report measurements of the photon beam asymmetry Σ for the reactions ⃗γp→pπ0 and ⃗γp→pη from the GlueX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π0 measurements and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.
Published: 2017
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32. Photon beam asymmetry $��$ for $��$ and $��^\prime$ photoproduction from the proton

Author: Collins, P., Ritchie, B. G., Dugger, M., Anisovich, A. V., D��ring, M., Klempt, E., Nikonov, V. A., R��nchen, D., Sadasivan, D., Sarantsev, A., Adhikaria, K. P., Akbar, Z., Amaryana, M. J., Pereira, S. Anefalos, Avakiana, H., Ball, J., Balossino, I., Bashkanova, M., Battaglieri, M., Bedlinskiy, I., Bisellik, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, Frank Thanh, Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Roy, P., Sabati��, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wei, X., Zachariou, N., and Zhang, J.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Measurements of the linearly-polarized photon beam asymmetry $��$ for photoproduction from the proton of $��$ and $��^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $��p \to ��p$ reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the $��p \to ��^\prime p$ reaction. For $��p \to ��p$, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For $��p \to ��^\prime p$, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn-Gatchina model strengthens the evidence for four nucleon resonances -- the $N(1895)1/2^-$, $N(1900)3/2^+$, $N(2100)1/2^+$ and $N(2120)3/2^-$ resonances -- which presently lack the "four-star" status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process., 10 pages, 3 figures
Published: 2017
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33. Measurement of the beam asymmetry $��$ for $��^0$ and $��$ photoproduction on the proton at $E_��= 9$ GeV

Author: GlueX Collaboration, Ghoul, H. Al, Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barnes, A., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Brooks, W. K., Cannon, B. E., Chernyshov, O., Chudakov, E., Crede, V., Dalton, M. M., Deur, A., Dobbs, S., Dolgolenko, A., Dugger, M., Dzhygadlo, R., Egiyan, H., Eugenio, P., Fanelli, C., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hardin, J., Henderson, A., Huber, G. M., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kamel, M., Klein, F. J., Kliemt, R., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Lara, M., Larin, I., Lawrence, D., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Mendez, R., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Moriya, K., Nerling, F., Nigmatkulov, G., Ochoa, N., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pedroni, R., Pennington, M. R., Pentchev, L., Peters, K. J., Pooser, E., Pratt, B., Qiang, Y., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Salgado, C., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Tarasov, V., Taylor, S., Teymurazyan, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Vasileiadis, G., Vega, I., Walford, N. K., Werthmuller, D., Whitlatch, T., Williams, M., Wolin, E., Xiao, T., Zarling, J., Zhang, Z., Zihlmann, B., Mathieu, V., and Nys, J.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report measurements of the photon beam asymmetry $��$ for the reactions $\vec��p\to p��^0$ and $\vec��p\to p��$ from the GlueX experiment using a 9 GeV linearly-polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous $��^0$ measurements and are the first $��$ measurements in this energy regime. The results are compared with theoretical predictions based on $t$-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models., 6 pages, 6 figures, Published in Physical Review C: Rapid Communication
Published: 2017
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34. Semi-Inclusive $��_0$ target and beam-target asymmetries from 6 GeV electron scattering with CLAS

Author: Jawalkar, S., Koirala, S., Avakian, H., Bosted, P., Griffioen, K. A., Keith, C., Kuhn, S. E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Bultmann, S., Burkert, V. D., Cao, Frank Thanh, Carlin, C., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Ddoge, G., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garcon, M., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Guidal, M., Guler, N., Guo, L., 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., 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., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, E., Phelps, W., Pierce, J., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatie, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stankovic, I., Strauch, S., Taiuti, M., 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 Zhao, Z. W.
Subjects: High Energy Physics - Phenomenology (hep-ph), Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic $^{14}$NH$_3$ target, and extracted double and single target spin asymmetries for $ep\rightarrow e^\prime��^0X$ in multidimensional bins in four-momentum transfer ($1.0, 18 preprint pages, 3 figures
Published: 2017
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35. Moments of the spin structure functions g1p and g1d for 0.05<Q2<3.0 GeV2

Author: Prok, Y., Bosted, P., Burkert, V.D., Deur, A., Dharmawardane, K.V., Dodge, G.E., Griffioen, K.A., Kuhn, S.E., Minehart, R., Adams, G., Amaryan, M.J., Anghinolfi, M., Asryan, G., Audit, G., Avakian, H., Bagdasaryan, H., Baillie, N., Ball, J.P., Baltzell, N.A., Barrow, S., Battaglieri, M., Beard, K., Bedlinskiy, I., Bektasoglu, M., Bellis, M., Benmouna, N., Berman, B.L., Biselli, A.S., Blaszczyk, L., Boiarinov, S., Bonner, B.E., Bouchigny, S., Bradford, R., Branford, D., Briscoe, W.J., Brooks, W.K., Bültmann, S., Butuceanu, C., Calarco, J.R., Careccia, S.L., Carman, D.S., Casey, L., Cazes, A., Chen, S., Cheng, L., Cole, P.L., Collins, P., Coltharp, P., Cords, D., Corvisiero, P., Crabb, D., Crede, V., Cummings, J.P., Dale, D., Dashyan, N., De Masi, R., De Vita, R., De Sanctis, E., Degtyarenko, P.V., Denizli, H., Dennis, L., Dhuga, K.S., Dickson, R., Djalali, C., Doughty, D., Dugger, M., Dytman, S., Dzyubak, O.P., Egiyan, H., Egiyan, K.S., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fatemi, R., Fedotov, G., Feldman, G., Fersh, R.G., Feuerbach, R.J., Forest, T.A., Fradi, A., Funsten, H., Garçon, M., Gavalian, G., Gevorgyan, N., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Golovatch, E., Gothe, R.W., Guidal, M., Guillo, M., Guler, N., Guo, L., Gyurjyan, V., Hadjidakis, C., Hafidi, K., Hakobyan, H., Hanretty, C., Hardie, J., Hassall, N., Heddle, D., Hersman, F.W., Hicks, K., Hleiqawi, I., Holtrop, M., Huertas, M., Hyde-Wright, C.E., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Ito, M.M., Jenkins, D., Jo, H.S., Johnstone, J.R., Joo, K., Juengst, H.G., Kalantarians, N., Keith, C.D., Kellie, J.D., Khandaker, M., Kim, K.Y., Kim, K., Kim, W., Klein, A., Klein, F.J., Klusman, M., Kossov, M., Krahn, Z., Kramer, L.H., Kubarovsky, V., Kuhn, J., Kuleshov, S.V., Kuznetsov, V., Lachniet, J., Laget, J.M., Langheinrich, J., Lawrence, D., Li, Ji, Lima, A.C.S., Livingston, K., Lu, H.Y., Lukashin, K., MacCormick, M., Marchand, C., Markov, N., Mattione, P., McAleer, S., McKinnon, B., McNabb, J.W.C., Mecking, B.A., Mestayer, M.D., Meyer, C.A., Mibe, T., Mikhailov, K., Mirazita, M., Miskimen, R., Mokeev, V., Morand, L., Moreno, B., Moriya, K., Morrow, S.A., Moteabbed, M., Mueller, J., Munevar, E., Mutchler, G.S., Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Niczyporuk, B.B., Niroula, M.R., Niyazov, R.A., Nozar, M., O'Rielly, G.V., Osipenko, M., Ostrovidov, A.I., Park, K., Pasyuk, E., Paterson, C., Pereira, S. Anefalos, Philips, S.A., Pierce, J., Pivnyuk, N., Pocanic, D., Pogorelko, O., Popa, I., Pozdniakov, S., Preedom, B.M., Price, J.W., Procureur, S., Protopopescu, D., Qin, L.M., Raue, B.A., Riccardi, G., Ricco, G., Ripani, M., Ritchie, B.G., Rosner, G., Rossi, P., Rowntree, D., Rubin, P.D., Sabatié, F., Salamanca, J., Salgado, C., Santoro, J.P., Sapunenko, V., Schumacher, R.A., Seely, M.L., Serov, V.S., Sharabian, Y.G., Sharov, D., Shaw, J., Shvedunov, N.V., Skabelin, A.V., Smith, E.S., Smith, L.C., Sober, D.I., Sokhan, D., Stavinsky, A., Stepanyan, S.S., Stepanyan, S., Stokes, B.E., Stoler, P., Strakovsky, I.I., Strauch, S., Suleiman, R., Taiuti, M., Tedeschi, D.J., Tkabladze, A., Tkachenko, S., Todor, L., Ungaro, M., Vineyard, M.F., Vlassov, A.V., Watts, D.P., Weinstein, L.B., Weygand, D.P., Williams, M., Wolin, E., Wood, M.H., Yegneswaran, A., Yun, J., Zana, L., Zhang, J., Zhao, B., and Zhao, Z.W.
Subjects: Nuclear and High Energy Physics
Published: 2009
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36. Target and Beam-Target Spin Asymmetries in Exclusive $��^+$ and $��^-$ Electroproduction with 1.6 to 5.7 GeV Electrons

Author: Bosted, P. E., Biselli, A. S., Careccia, S., Dodge, G., Fersch, R., Kuhn, S. E., Pierce, J., Prok, Y., Zheng, X., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Boiarinov, S., Briscoe, W. J., B��ltmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gar��on, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guler, N., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., McCracken, M. E., McKinnon, B., Meyer, C. A., Minehart, R., Mirazita, M., Mokeev, V., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabati��, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sparveris, N., Stankovic, Ivana, Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Theory, Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $��^+$ and $��^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $��^+$) and deuterons (for $��^-$) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is $1.11.5$ GeV. Very large target-spin asymmetries are observed for $W>1.6$ GeV. When combined with cross section measurements, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of $Q^2$, for resonances with masses as high as 2.3 GeV., 47 pages, 24 figures. This is a revised version that was accepted for publication in Phys. Rev. C. in early October, 2016
Published: 2016
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37. Target and beam-target spin asymmetries in exclusive pion electroproduction for $Q^2>1$ GeV$^2$. II. $e p \rightarrow e ��^0 p$

Author: Bosted, P. E., Kim, A., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., B��ltmann, 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., Alaoui, A. El, Fassi, L. El, 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, Camacho, C. Munoz, 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., Sabati��, 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: Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $��^0$ electroproduction reaction $��^* p \to p ��^0$, expanding an analysis of the $��^* p \to n ��^+$ 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 Lab. The kinematic range covered is $1.1, 28 pages, 12 figures, submitted to Phys. Rev. C
Published: 2016
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38. Measurement of Target and Double-spin Asymmetries for the $\vec e\vec p\to e��^+ (n)$ Reaction in the Nucleon Resonance Region at Low $Q^2$

Author: Zheng, X., Adhikari, K. P., Bosted, P., Deur, A., Drozdov, V., Fassi, L. El, 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., Pereira, S. Anefalos, Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., B��ltmann, 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., Alaoui, A. El, 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., Camacho, C. Munoz, 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., Sabati��, 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., and Zhang, J.
Subjects: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e��^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models., 20 pages, 15 figures, to appear in Phys. Rev. C
Published: 2016
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39. Measurement of the x- and Q2-dependence of the asymmetry A1 on the nucleon

Author: Dharmawardane, K.V., Kuhn, S.E., Bosted, P., Prok, Y., Adams, G., Ambrozewicz, P., Anghinolfi, M., Asryan, G., Avakian, H., Bagdasaryan, H., Baillie, N., Ball, J.P., Baltzell, N.A., Barrow, S., Batourine, V., Battaglieri, M., Beard, K., Bedlinskiy, I., Bektasoglu, M., Bellis, M., Benmouna, N., Biselli, A.S., Bonner, B.E., Bouchigny, S., Boiarinov, S., Bradford, R., Branford, D., Brooks, W.K., Bültmann, S., Burkert, V.D., Butuceanu, C., Calarco, J.R., Careccia, S.L., Carman, D.S., Carnahan, B., Cazes, A., Chen, S., Cole, P.L., Collins, P., Coltharp, P., Cords, D., Corvisiero, P., Crabb, D., Crannell, H., Crede, V., Cummings, J.P., De Masi, R., DeVita, R., De Sanctis, E., Degtyarenko, P.V., Denizli, H., Dennis, L., Deur, A., Djalali, C., Dodge, G.E., Donnelly, J., Doughty, D., Dragovitsch, P., Dugger, M., Dytman, S., Dzyubak, O.P., Egiyan, H., Egiyan, K.S., Elouadrhiri, L., Eugenio, P., Fatemi, R., Fedotov, G., Feuerbach, R.J., Forest, T.A., Funsten, H., Garçon, M., Gavalian, G., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Goetz, J.T., Golovatch, E., Gonenc, A., Gothe, R.W., Griffioen, K.A., Guidal, M., Guillo, M., Guler, N., Guo, L., Gyurjyan, V., Hadjidakis, C., Hafidi, K., Hakobyan, R.S., Hardie, J., Heddle, D., Hersman, F.W., Hicks, K., Hleiqawi, I., Holtrop, M., Huertas, M., Hyde-Wright, C.E., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Ito, M.M., Jenkins, D., Jo, H.S., Joo, K., Juengst, H.G., Keith, C., Kellie, J.D., Khandaker, M., Kim, K.Y., Kim, K., Kim, W., Klein, A., Klein, F.J., Klusman, M., Kossov, M., Kramer, L.H., Kubarovsky, V., Kuhn, J., Kuleshov, S.V., Lachniet, J., Laget, J.M., Langheinrich, J., Lawrence, D., Li, Ji, Lima, A.C.S., Livingston, K., Lu, H., Lukashin, K., MacCormick, M., Manak, J.J., Markov, N., McAleer, S., McKinnon, B., McNabb, J.W.C., Mecking, B.A., Mestayer, M.D., Meyer, C.A., Mibe, T., Mikhailov, K., Minehart, R., Mirazita, M., Miskimen, R., Mokeev, V., Morand, L., Morrow, S.A., Moteabbed, M., Mueller, J., Mutchler, G.S., Nadel-Turonski, P., Napolitano, J., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Niczyporuk, B.B., Niroula, M.R., Niyazov, R.A., Nozar, M., O'Rielly, G.V., Osipenko, M., Ostrovidov, A.I., Park, K., Pasyuk, E., Paterson, C., Philips, S.A., Pierce, J., Pivnyuk, N., Pocanic, D., Pogorelko, O., Polli, E., Pozdniakov, S., Preedom, B.M., Price, J.W., Protopopescu, D., Qin, L.M., Raue, B.A., Riccardi, G., Ricco, G., Ripani, M., Ritchie, B.G., Ronchetti, F., Rosner, G., Rossi, P., Rowntree, D., Rubin, P.D., Sabatié, F., Salgado, C., Santoro, J.P., Sapunenko, V., Schumacher, R.A., Serov, V.S., Sharabian, Y.G., Shaw, J., Shvedunov, N.V., Skabelin, A.V., Smith, E.S., Smith, L.C., Sober, D.I., Stavinsky, A., Stepanyan, S.S., Stepanyan, S., Stokes, B.E., Stoler, P., Strakovsky, I.I., Strauch, S., Suleiman, R., Taiuti, M., Taylor, S., Tedeschi, D.J., Thoma, U., Thompson, R., Tkabladze, A., Tkachenko, S., Todor, L., Tur, C., Ungaro, M., Vineyard, M.F., Vlassov, A.V., Weinstein, L.B., Weygand, D.P., Williams, M., Wolin, E., Wood, M.H., Yegneswaran, A., Yun, J., Zana, L., Zhang, J., Zhao, B., and Zhao, Z.
Subjects: Nuclear and High Energy Physics
Published: 2006
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40. Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region $E_��=1.1-2.3$ GeV

Author: Zachariou, Nicholas, Ilieva, Yordanka, Ivanov, Nikolay Ya., Sargsian, Misak M, Avakian, Robert, Feldman, Gerald, Nadel-Turonski, Pawel, Adhikari, K. P., Adikaram, D., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Badui, R. A., Baltzell, N. A., Battaglieri, M., Baturin, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mattione, P. T., McKinnon, B., Mineeva, T., Mirazita, M., Mokeeev, V. I., Montgomery, R. A., Moutarde, H., Camacho, C. Munoz, Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabati��, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stepanyan, S., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Wood, M. H., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The beam-spin asymmetry, $��$, for the reaction $��d\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $��_{c.m.}$, between $25^\circ$ and $160^\circ$. These are the first measurements of beam-spin asymmetries at $��_{c.m.}=90^\circ$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than $��_{c.m.}=90^\circ$. The angular and energy dependence of $��$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions., 18 pages
Published: 2015
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41. First Measurement of the Polarization Observable E in the $\vec p(\vec ��,��^+)n$ Reaction up to 2.25 GeV

Author: Strauch, S., Briscoe, W. J., D��ring, M., Klempt, E., Nikonov, V. A., Pasyuk, E., R��nchen, D., Sarantsev, A. V., Strakovsky, I., Workman, R., Adhikari, K. P., Adikaram, D., Anderson, M. D., Pereira, S. Anefalos, Anisovich, A. V., Badui, R. A., Ball, J., Batourine, V., Battaglieri, M., Bedlinskiy, I., Benmouna, N., Biselli, A. S., Brock, J., Brooks, W. K., Burkert, V. D., Cao, T., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., Dashyan, N., D'Angelo, A., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., McKinnon, B., Meekins, D. G., Meyer, C. A., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Peng, P., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Roy, P., Sabati��, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seely, M. L., Senderovich, I, Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stoler, P., Stepanyan, S., Sytnik, V., Taiuti, M., Tian, Ye, Trivedi, A., Tucker, R., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction $\vec ��\vec p \to ��^+n$, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, J��lich, and SAID groups., 6 pages, 3 figures
Published: 2015
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42. Target and Double Spin Asymmetries of Deeply Virtual $��^0$ Production with a Longitudinally Polarized Proton Target and CLAS

Author: Kim, A., Avakian, H., Burkert, V., Joo, K., Kim, W., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Badui, R. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Bosted, P., Briscoe, W. J., Brooks, W. K., B��ltmann, S., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., 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., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Fradi, A., Gar��on, M., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hanretty, C., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mattione, P., McCracken, M. E., McKinnon, B., Mokeev, V., Movsisyan, A, Munevar, E., Nadel-Turonski, P., Net, L. A., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zana, L., Zhang, J., and Zonta, I.
Subjects: FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep��^0$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of $Q^2$, $x_B$, $-t$ and $��$. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs $\tilde{H}_T$ and $E_T$, and complement previous measurements of unpolarized structure functions sensitive to the GPDs $H_T$ and $\bar E_T$. These data provide necessary constraints for chiral-odd GPD parametrizations and will strongly influence existing theoretical handbag models.
Published: 2015
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43. First measurement of the helicity asymmetry $E$ in $��$ photoproduction on the proton

Author: Senderovich, I., Morrison, B. T., Dugger, M., Ritchie, B. G., Pasyuk, E., Tucker, R., Brock, J., Carlin, C., Keith, C. D., Meekins, D. G., Seely, M. L., R, D., D, M., Collins, P., Adhikari, K. P., Adikaram, D., Akbar, Z., Anderson, M. D., Pereira, S. Anefalos, Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Fradi, A., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Garillon, B., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. -X., Glazier, D. I., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Klein, F. J., Kubarovsky, V., Kunkel, M. C., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mattione, P., McKinnon, B., Meyer, C. A., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Park, K., Park, S., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Puckett, A. J. R., Ripani, M., Rizzo, A., Rosner, G., Roy, P., Sabatie, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Sytnik, V., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Results are presented for the first measurement of the double-polarization helicity asymmetry E for the $��$ photoproduction reaction $��p \rightarrow ��p$. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the J��lich model to examine the case for the existence of a narrow $N^*$ resonance between 1.66 and 1.70 GeV. The addition of these data to the world database results in marked changes in the predictions for the E observable using that model. Further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances.
Published: 2015
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44. Nuclear physics. Momentum sharing in imbalanced Fermi systems

Author: Hen, O, Sargsian, M, Weinstein, L. B, Piasetzky, E, Hakobyan, H, Higinbotham, D. W, Braverman, M, Brooks, W. K, Gilad, S, Adhikari, K. P, Arrington, J, Asryan, G, Avakian, H, Ball, J, Baltzell, N. A, Battaglieri, M, Beck, A, May Tal Beck, S, Bedlinskiy, I, Bertozzi, W, Biselli, A, Burkert, V. D, Cao, T, Carman, D. S, Celentano, A, Chandavar, S, Colaneri, L, Cole, P. L, Crede, V, D'Angelo, A, De Vita, R, Deur, A, Djalali, C, Doughty, D, Dugger, M, Dupre, R, Egiyan, H, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Fedotov, G, Fegan, S, Forest, T, Garillon, B, Garcon, M, Gevorgyan, N, Ghandilyan, Y, Gilfoyle, G. P, Girod, F. X, Goetz, J. T, Gothe, R. W, Griffioen, K. A, Guidal, M, Guo, L, Hafidi, K, Hanretty, C, Hattawy, M, Hicks, K, Holtrop, M, Hyde, C. E, Ilieva, Y, Ireland, D. G, Ishkanov, B. I, Isupov, E. L, Jiang, H, H. S, Jo, Joo, K, Keller, D, Khandaker, M, Kim, A, Kim, W, Klein, F. J, Koirala, S, Korover, I, Kuhn, S. E, Kubarovsky, V, Lenisa, Paolo, Levine, W. I, Livingston, K, Lowry, M, H. Y, Lu, Macgregor, I. J. D, Markov, N, Mayer, M, Mckinnon, B, Mineeva, T, Mokeev, V, Movsisyan, A, Munoz Camacho, C, Mustapha, B, Nadel Turonski, P, Niccolai, S, Niculescu, G, Niculescu, I, Osipenko, M, Pappalardo, L. L, Paremuzyan, R, Park, K, Pasyuk, E, Phelps, W, Pisano, S, Pogorelko, O, Price, J. W, Procureur, S, Prok, Y, Protopopescu, D, Puckett, A. J. R, Rimal, D, Ripani, M, Ritchie, B. G, Rizzo, A, Rosner, G, Roy, P, Rossi, P, Sabatié, F, Schott, D, Schumacher, R. A, Sharabian, Y. G, Smith, G. D, Shneor, R, Sokhan, D, Stepanyan, S. S, Stepanyan, S, Stoler, P, Strauch, S, Sytnik, V, Taiuti, M, Tkachenko, S, Ungaro, M, Vlassov, A. V, Voutier, E, Walford, N. K, Wei, X, Wood, M. H, Wood, S. A, Zachariou, N, Zana, L, Zhao, Z. W, Zheng, X, and Zonta, I.
Subjects: NO
Abstract: The atomic nucleus is composed of two different kinds of fermions: protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority of fermions (usually neutrons) to have a higher average momentum. Our high-energy electron-scattering measurements using (12)C, (27)Al, (56)Fe, and (208)Pb targets show that even in heavy, neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few-body systems to neutron stars and may also be observable experimentally in two-spin-state, ultracold atomic gas systems.
Published: 2014

45. Exclusive $��^0$ electroproduction at $W>2$ GeV with CLAS

Author: Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Biselli, A. S., Boiarinov, S., Bono, J., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., 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., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Garillon, B., Gar��on, M., Gavalian, G., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Levine, W. I., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mirazita, M., Mokeev, V., Montgomery, R. A., Moody, C. I., Moutarde, H., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Park, K., Park, S., Pasyuk, E., Phelps, E., Phelps, W., Phillips, J. J., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Procureur, S., Puckett, A. J. R., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rossi, P., Roy, P., Sabati��, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Senderovich, I., Sharabian, Y. G., Simonyan, A., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Strauch, S., Sytnik, V., Tang, W., Tian, Ye, Ungaro, M., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D., Wei, X., Weinstein, L. B., Yurov, M., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: Exclusive neutral-pion electroproduction ($ep\to e^\prime p^\prime ��^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4��/dtdQ^2dx_Bd��_��$ and structure functions $��_T+��_L, ��_{TT}$ and $��_{LT}$ as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions., 28 pages, 25 figures, Submitted to Phys. Rev. C
Published: 2014
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46. A study of decays to strange final states with GlueX in Hall D using components of the BaBar DIRC

Author: The GlueX Collaboration, Dugger, M., Ritchie, B., Senderovich, I., Anassontzis, E., Ioannou, P., Kourkoumeli, C., Vasileiadis, G., Voulgaris, G., Jarvis, N., Levine, W., Mattione, P., McGinley, W., Meyer, C. A., Schumacher, R., Staib, M., Klein, F., Sober, D., Sparks, N., Walford, N., Doughty, D., Barnes, A., Jones, R., McIntyre, J., Mokaya, F., Pratt, B., Boeglin, W., Guo, L., Pooser, E., Reinhold, J., Ghoul, H. Al, Crede, V., Eugenio, P., Ostrovidov, A., Tsaris, A., Ireland, D., Livingston, K., Bennett, D., Bennett, J., Frye, J., Lara, M., Leckey, J., Mitchell, R., Moriya, K., Shepherd, M. R., Chernyshov, O., Dolgolenko, A., Gerasimov, A., Goryachev, V., Larin, I., Matveev, V., Tarasov, V., Barbosa, F., Chudakov, E., Dalton, M., Deur, A., Dudek, J., Egiyan, H., Furletov, S., Ito, M., Mack, D., Lawrence, D., McCaughan, M., Pennington, M., Pentchev, L., Qiang, Y., Smith, E., Somov, A., Taylor, S., Whitlatch, T., Zihlmann, B., Miskimen, R., Guegan, B., Hardin, J., Stevens, J., Williams, M., Berdnikov, V., Nigmatkulov, G., Ponosov, A., Romanov, D., Somov, S., Tolstukhin, I., Salgado, C., Ambrozewicz, P., Gasparian, A., Pedroni, R., Black, T., Gan, L., Dobbs, S., Seth, K., Ting, X., Tomaradze, A., Beattie, T., Huber, G., Lolos, G., Papandreou, Z., Semenov, A., Semenova, I., Brooks, W., Hakobyan, H., Kuleshov, S., Soto, O., Toro, A., Vega, I., Gevorgyan, N., and Kakoyan, V.
Subjects: High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, FOS: Physical sciences, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), High Energy Physics - Experiment
Abstract: We propose to enhance the kaon identification capabilities of the GlueX detector by constructing an FDIRC (Focusing Detection of Internally Reflected Cherenkov) detector utilizing the decommissioned BaBar DIRC components. The GlueX FDIRC would significantly enhance the GlueX physics program by allowing one to search for and study hybrid mesons decaying into kaon final states. Such systematic studies of kaon final states are essential for inferring the quark flavor content of hybrid and conventional mesons. The GlueX FDIRC would reuse one-third of the synthetic fused silica bars that were utilized in the BaBar DIRC. A new focussing photon camera, read out with large area photodetectors, would be developed. We propose operating the enhanced GlueX detector in Hall D for a total of 220 days at an average intensity of 5x10^7 {\gamma}/s, a program that was conditionally approved by PAC39, Comment: 25 pages, 29 figures
Published: 2014
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47. Spin and parity measurement of the Lambda(1405) baryon

Author: Moriya, K., Schumacher, R.A., Aghasyan, M., Amaryan, M.J., Anderson, M.D., Anefalos Pereira, S., Ball, J., Baltzell, N.A., Battaglieri, M., Bellis, M., Biselli, A.S., Bono, J., Boiarinov, S., Briscoe, W.J., Brooks, W.K., Burkert, V.D., Carman, D.S., Celentano, A., Chandavar, S., Charles, G., Cole, P.L., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Dey, B., Djalali, C., Dugger, M., Dupré, R., Egiyan, H., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J.A., Gilfoyle, G.P., Giovanetti, K.L., Girod, F.X., Gohn, W., Golovatch, E., Gothe, R.W., Guidal, M., Griffioen, K.A., Hafidi, K., Hakobyan, H., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Ishkhanov, B.S., Isupov, E.L., Jo, H.S., Joo, K., Keller, D., Khandaker, M., Kim, W., Koirala, S., Kubarovsky, V., Kuleshov, S.V., Lenisa, P., Lu, H.Y., Macgregor, I.J.D., Markov, N., Mccracken, M., Mckinnon, B., Mestayer, M.D., Meyer, C.A., Mirazita, M., Mokeev, V., Montgomery, R.A., Moutarde, H., Munevar, E., Nadel-Turonski, P., Niccolai, S., Niculescu, I., Osipenko, M., Pappalardo, L.L., Pasyuk, E., Peng, P., Phillips, J.J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J.W., Procureur, S., Puckett, A.J.R., Raue, B.A., Rimal, D., Ripani, M., Ritchie, B.G., Rizzo, A., Rosner, G., Roy, Pascal, Sabatié, F., Salgado, C., Schott, D., Seder, E., Senderovich, I., Smith, E.S., Sokhan, D., Smith, G.D., Stepanyan, S., Strauch, S., Tang, W., Voskanyan, H., Voutier, E., Walford, N.K., Watts, D.P., Weinstein, L.B., Williams, M., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., Ziegler, V., Zhao, Z.W., Zonta, I., Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], FOS: Physical sciences, High Energy Physics::Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract: A determination of the spin and parity of the $\Lambda(1405)$ is presented using photoproduction data from the CLAS detector at Jefferson Lab. The reaction $\gamma + p \to K^+ + \Lambda(1405)$ is analyzed in the decay channel $\Lambda(1405) \to \Sigma^+ + \pi^-$, where the decay distribution to $\Sigma^+ \pi^-$ and the variation of the $\Sigma^+$ polarization with respect to the $\Lambda(1405)$ polarization direction determines the parity. The $\Lambda(1405)$ is produced, in the energy range $2.55 < W < 2.85$ GeV and for $0.6 < \cos \theta_{K^+} < 0.9$, with polarization $P = 0.45 \pm 0.02 (\text{stat}) \pm 0.07 (\text{syst})$. The analysis shows that the decays are in $S$ wave, with the $\Sigma^+$ polarized such that the $\Lambda(1405)$ has spin-parity $J^P = 1/2^-$, as expected by most theories., Comment: 6 pages, 4 figures, accepted by Phys. Rev. Lett
Published: 2014
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48. Measurement of exclusive π(0) electroproduction structure functions and their relationship to transverse generalized parton distributions

Author: Bedlinskiy, I, Kubarovsky, V, Niccolai, S, Stoler, P, Adhikari, K, Aghasyan, M, Amaryan, M, Anghinolfi, M, Avakian, H, Baghdasaryan, H, Ball, J, Baltzell, N, Battaglieri, M, Bennett, R, Biselli, A, Bookwalter, C, Boiarinov, S, Briscoe, W, Brooks, W, Burkert, V, Carman, D, Celentano, A, Chandavar, S, Charles, G, Contalbrigo, M, Crede, V, D'Angelo, A, Daniel, A, Dashyan, N, De Vita, R, De Sanctis, E, Deur, A, Djalali, C, Doughty, D, Dupre, R, Egiyan, H, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Eugenio, P, Fedotov, G, Fegan, S, Fleming, J, Forest, T, Fradi, A, Garcon, M, Gevorgyan, N, Giovanetti, K, Girod, F, Gohn, W, Gothe, R, Graham, L, Griffioen, K, Guegan, B, Guidal, M, Guo, L, Hafidi, K, Hakobyan, H, Hanretty, C, Heddle, D, Hicks, K, Holtrop, M, Ilieva, Y, Ireland, D, Ishkhanov, B, Isupov, E, Jo, H, Joo, K, Keller, D, Khandaker, M, Khetarpal, P, Kim, A, Kim, W, Klein, F, Koirala, S, Kubarovsky, A, Kuhn, S, Kuleshov, S, Kvaltine, N, Livingston, K, Lu, H, Macgregor, I, Mao, Y, Markov, N, Martinez, D, Mayer, M, Mckinnon, B, Meyer, C, Mineeva, T, Mirazita, M, Mokeev, V, Moutarde, H, Munevar, E, Camacho, C, Nadel Turonski, P, Niculescu, G, Niculescu, I, Osipenko, M, Ostrovidov, A, Pappalardo, L, Paremuzyan, R, Park, K, Park, S, Pasyuk, E, Pereira, S, Phelps, E, Pisano, S, Pogorelko, O, Pozdniakov, S, Price, J, Procureur, S, Prok, Y, Protopopescu, D, Puckett, A, Raue, B, Ricco, G, Rimal, D, Ripani, M, Rosner, G, Rossi, P, Sabatie, F, Saini, M, Salgado, C, Saylor, N, Schott, D, Schumacher, R, Seder, E, Seraydaryan, H, Sharabian, Y, Smith, G, Sober, D, Sokhan, D, Stepanyan, S, Strauch, S, Taiuti, M, Tang, W, Taylor, C, Tian, Y, Tkachenko, S, Ungaro, M, Vineyard, M, Vlassov, A, Voskanyan, H, Voutier, E, Walford, N, Watts, D, Weinstein, L, Weygand, D, Wood, M, Zachariou, N, Zhang, J, Zhao, Z, and Zonta, I
Subjects: PION ELECTROPRODUCTION, Settore FIS/04 - Fisica Nucleare e Subnucleare
Abstract: Exclusive π(0) electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in Q(2), x(B), t, and ϕ(π), in the Q(2) range from 1.0 to 4.6 GeV(2), -t up to 2 GeV(2), and x(B) from 0.1 to 0.58. Structure functions σ(T)+ϵσ(L), σ(TT), and σ(LT) were extracted as functions of t for each of 17 combinations of Q(2) and x(B). The data were compared directly with two handbag-based calculations including both longitudinal and transversity generalized parton distributions (GPDs). Inclusion of only longitudinal GPDs very strongly underestimates σ(T)+ϵσ(L) and fails to account for σ(TT) and σ(LT), while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity-flip and helicity nonflip processes. The results confirm that exclusive π(0) electroproduction offers direct experimental access to the transversity GPDs.
Published: 2012

49. Deep exclusive $��^+$ electroproduction off the proton at CLAS

Author: Park, K., Guidal, M., Gothe, R. W., Laget, J. M., Gar��on, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinsky, I., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Fradi, A., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Graham, L., Griffioen, K. A., Guegan, B., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nepali, C. S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Trivedi, A., Ungaro, M., Vernarsky, B ., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract: The exclusive electroproduction of $��^+$ above the resonance region was studied using the $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\rm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the $��^* p \to n ��^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16, 18pages, 21figures,2tables
Published: 2012
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50. Evidence for the Onset of Color Transparency in $��^0$ Electroproduction off Nuclei

Author: Fassi, L. El, Zana, L., Hafidi, K., Holtrop, M., Mustapha, B., Brooks, W. K., Hakobyan, H., Zheng, X., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Arrington, J., Avakian, H., Baghdasaryan, H., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bookwalter, C., Branford, D., Briscoe, W. J., Bultmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dey, B., Dickson, R., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Gabrielyan, M. Y., Garcon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hanretty, C., Heddle, D., Hicks, K., Holt, R. J., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jawalkar, S. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kuznetsov, V., Laget, J. M., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Mayer, M., McAndrew, J., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moreno, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Raue, B. A., Reimer, P. E., 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., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tedeschi, D. J., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vineyard, M. F., Voskanyan, H., Voutier, E., Watts, D., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhao, B., and Zhao, Z. W.
Subjects: FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: We have measured the nuclear transparency of the incoherent diffractive $A(e,e'��^0)$ process in $^{12}$C and $^{56}$Fe targets relative to $^2$H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced $��^0$'s on a nucleus relative to deuterium, which is sensitive to $��A$ interaction, was studied as function of the coherence length ($l_c$), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared ($Q^2$). While the transparency for both $^{12}$C and $^{56}$Fe showed no $l_c$ dependence, a significant $Q^2$ dependence was measured, which is consistent with calculations that included the color transparency effects., 6 pages and 4 figures
Published: 2012
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