N. Sparveris - The CLAS Collaboration

N. Sparveris
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N. Sparveris
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The CLAS Collaboration
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Nuclear Experiment (37)
 
High Energy Physics - Experiment (7)
 
High Energy Physics - Phenomenology (2)
 
Nuclear Theory (1)
 
Physics - Instrumentation and Detectors (1)

Publications Authored By N. Sparveris

2017May
Authors: D. Ho, P. Peng, C. Bass, P. Collins, A. D'Angelo, A. Deur, J. Fleming, C. Hanretty, T. Kageya, M. Khandaker, F. J. Klein, E. Klempt, V. Laine, M. M. Lowry, H. Lu, C. Nepali, V. A. Nikonov, T. O'Connell, A. M. Sandorfi, A. V. Sarantsev, R. A. Schumacher, I. I. Strakovsky, A. Švarc, N. K. Walford, X. Wei, C. S. Whisnant, R. L. Workman, I. Zonta, K. P. Adhikari, D. Adikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, H. Avakian, J. Ball, M. Bashkanov, M. Battaglieri, V. Batourine, I. Bedlinskiy, W. J. Briscoe, V. D. Burkert, D. S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, M. Contalbrigo, V. Crede, N. Dashyan, E. De Sanctis, R. De Vita, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, G. Fedotov, S. Fegan, R. Fersch, A. Filippi, A. Fradi, Y. Ghandilyan, G. P. Gilfoyle, F. X. Girod, D. I. Glazier, C. Gleason, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, H. Hakobyan, N. Harrison, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, H. S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, A. Kim, W. Kim, A. Klein, V. Kubarovsky, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I . J . D. MacGregor, N. Markov, B. McKinnon, T. Mineeva, V. Mokeev, R. A. Montgomery, A Movsisyan, C. Munoz Camacho, G. Murdoch, S. Niccolai, G. Niculescu, M. Osipenko, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, O. Pogorelko, J. W. Price, S. Procureur, D. Protopopescu, M. Ripani, D. Riser, B. G. Ritchie, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. I. Sober, D. Sokhan, N. Sparveris, S. Strauch, Ye Tian, B. Torayev, M. Ungaro, H. Voskanyan, D. P. Watts, M. H. Wood, N. Zachariou, J. Zhang, Z. W. Zhao

We report the first beam-target double-polarization asymmetries in the $\gamma + n(p) \rightarrow \pi^- + p(p)$ reaction spanning the nucleon resonance region from invariant mass $W$= $1500$ to $2300$ MeV. Circularly polarized photons and longitudinally polarized deuterons in $H\!D$ have been used with the CLAS detector at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the {\it{E}} polarization observable for an effective neutron target. Read More

2017Mar
Authors: CLAS Collaboration, I. Bedlinskiy, V. Kubarovsky, P. Stoler, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, H. Avakian, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, A. S. Biselli, S. Boiarinov, W. J. Briscoe, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, E. Fanchini, G. Fedotov, R. Fersch, A. Filippi, J. A. Fleming, T. A. Forest, M. Garçon, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, C. Gleason, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, S. M. Hughes, C. E. Hyde, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, H. S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, F. J. Klein, S. E. Kuhn, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I. J. D. MacGregor, N. Markov, B. McKinnon, Z. E. Meziani, M. Mirazita, V. Mokeev, R. A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L. A. Net, A. Ni, S. Niccolai, G. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, P. Peng, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, A. J. R. Puckett, B. A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatié, M. S. Saini, C. Salgado, R. A. Schumacher, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I. I. Strakovsky, S. Strauch, M. Taiuti, Ye Tian, B. Torayev, M. Turisini, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, L. B. Weinstein, M. H. Wood, M. Yurov, N. Zachariou, J. Zhang, I. Zonta

The cross section of the exclusive $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\eta$ and structure functions $\sigma_U = \sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$, as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. Read More

2017Mar
Authors: P. Collins, B. G. Ritchie, M. Dugger, A. V. Anisovich, M. Döring, E. Klempt, V. A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, K. P. Adhikaria, Z. Akbar, M. J. Amaryana, S. Anefalos Pereira, H. Avakiana, J. Ball, I. Balossino, M. Bashkanova, M. Battaglieri, I. Bedlinskiy, A. S. Bisellik, W. J. Briscoe, W. K. Brooks, V. D. Burkert, Frank Thanh Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, E. Fanchini, G. Fedotov, A. Filippi, J. A. Fleming, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, D. I. Glazier, C. Gleason, E. Golovatch, R. W. Gothe, K. A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, D. Heddle, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I. J. D. MacGregor, N. Markov, B. McKinnon, C. A. Meyer, M. Mirazita, V. Mokeev, R. A. Montgomery, A Movsisyan, C. Munoz Camacho, G. Murdoch, P. Nadel-Turonski, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, B. A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, R. A. Schumacher, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I. I. Strakovsky, S. Strauch, M. Taiuti, Ye Tian, B. Torayev, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, X. Wei, N. Zachariou, J. Zhang

Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $\gamma p \to \eta p$ reaction for incident photon energies from 1. Read More

2016Nov
Authors: P. E. Bosted1, A. Kim2, K. P. Adhikari3, D. Adikaram4, Z. Akbar5, M. J. Amaryan6, S. Anefalos Pereira7, H. Avakian8, R. A. Badui9, J. Ball10, I. Balossino11, M. Battaglieri12, I. Bedlinskiy13, A. S. Biselli14, S. Boiarinov15, W. J. Briscoe16, W. K. Brooks17, S. Bültmann18, V. D. Burkert19, T. Cao20, D. S. Carman21, A. Celentano22, S. Chandavar23, G. Charles24, T. Chetry25, G. Ciullo26, L. Clark27, L. Colaneri28, P. L. Cole29, M. Contalbrigo30, O. Cortes31, V. Crede32, A. D'Angelo33, N. Dashyan34, R. De Vita35, E. De Sanctis36, A. Deur37, C. Djalali38, R. Dupre39, H. Egiyan40, A. El Alaoui41, L. El Fassi42, L. Elouadrhiri43, P. Eugenio44, E. Fanchini45, G. Fedotov46, S. Fegan47, R. Fersch48, A. Filippi49, J. A. Fleming50, T. A. Forest51, A. Fradi52, Y. Ghandilyan53, G. P. Gilfoyle54, F. X. Girod55, D. I. Glazier56, W. Gohn57, E. Golovatch58, R. W. Gothe59, K. A. Griffioen60, M. Guidal61, N. Guler62, H. Hakobyan63, L. Guo64, K. Hafidi65, H. Hakobyan66, C. Hanretty67, N. Harrison68, M. Hattawy69, D. Heddle70, K. Hicks71, G. Hollis72, M. Holtrop73, S. M. Hughes74, D. G. Ireland75, E. L. Isupov76, D. Jenkins77, H. Jiang78, H. S. Jo79, K. Joo80, D. Keller81, G. Khachatryan82, M. Khandaker83, W. Kim84, A. Klei85, F. J. Klein86, S. Koirala87, V. Kubarovsky88, S. E. Kuhn89, L. Lanza90, P. Lenisa91, K. Livingston92, H. Y. Lu93, I. J. D. MacGregor94, N. Markov95, M. Mayer96, M. E. McCracken97, B. McKinnon98, T. Mineeva99, M. Mirazita100, V. I. Mokeev101, R. A. Montgomery102, A Movsisyan103, C. Munoz Camacho104, G. Murdoch105, P. Nadel-Turonski106, A. Ni107, S. Niccolai108, G. Niculescu109, M. Osipenko110, A. I. Ostrovidov111, M. Paolone112, R. Paremuzyan113, K. Park114, E. Pasyuk115, W. Phelps116, S. Pisano117, O. Pogorelko118, J. W. Price119, Y. Prok120, D. Protopopescu121, A. J. R. Puckett122, B. A. Raue123, M. Ripani124, A. Rizzo125, G. Rosner126, P. Rossi127, P. Roy128, F. Sabatié129, M. S. Saini130, R. A. Schumacher131, E. Seder132, Y. G. Sharabian133, Iu. Skorodumina134, G. D. Smith135, D. Sokhan136, N. Sparveris137, I. Stankovic138, S. Stepanyan139, P. Stoler140, I. I. Strakovsky141, S. Strauch142, M. Taiuti143, Ye Tian144, B. Torayev145, M. Ungaro146, H. Voskanyan147, E. Voutier148, N. K. Walford149, D. P. Watts150, X. Wei151, L. B. Weinstein152, N. Zachariou153, J. Zhang154, Z. W. Zhao155, I. Zonta156
Affiliations: 1The CLAS Collaboration, 2The CLAS Collaboration, 3The CLAS Collaboration, 4The CLAS Collaboration, 5The CLAS Collaboration, 6The CLAS Collaboration, 7The CLAS Collaboration, 8The CLAS Collaboration, 9The CLAS Collaboration, 10The CLAS Collaboration, 11The CLAS Collaboration, 12The CLAS Collaboration, 13The CLAS Collaboration, 14The CLAS Collaboration, 15The CLAS Collaboration, 16The CLAS Collaboration, 17The CLAS Collaboration, 18The CLAS Collaboration, 19The CLAS Collaboration, 20The CLAS Collaboration, 21The CLAS Collaboration, 22The CLAS Collaboration, 23The CLAS Collaboration, 24The CLAS Collaboration, 25The CLAS Collaboration, 26The CLAS Collaboration, 27The CLAS Collaboration, 28The CLAS Collaboration, 29The CLAS Collaboration, 30The CLAS Collaboration, 31The CLAS Collaboration, 32The CLAS Collaboration, 33The CLAS Collaboration, 34The CLAS Collaboration, 35The CLAS Collaboration, 36The CLAS Collaboration, 37The CLAS Collaboration, 38The CLAS Collaboration, 39The CLAS Collaboration, 40The CLAS Collaboration, 41The CLAS Collaboration, 42The CLAS Collaboration, 43The CLAS Collaboration, 44The CLAS Collaboration, 45The CLAS Collaboration, 46The CLAS Collaboration, 47The CLAS Collaboration, 48The CLAS Collaboration, 49The CLAS Collaboration, 50The CLAS Collaboration, 51The CLAS Collaboration, 52The CLAS Collaboration, 53The CLAS Collaboration, 54The CLAS Collaboration, 55The CLAS Collaboration, 56The CLAS Collaboration, 57The CLAS Collaboration, 58The CLAS Collaboration, 59The CLAS Collaboration, 60The CLAS Collaboration, 61The CLAS Collaboration, 62The CLAS Collaboration, 63The CLAS Collaboration, 64The CLAS Collaboration, 65The CLAS Collaboration, 66The CLAS Collaboration, 67The CLAS Collaboration, 68The CLAS Collaboration, 69The CLAS Collaboration, 70The CLAS Collaboration, 71The CLAS Collaboration, 72The CLAS Collaboration, 73The CLAS Collaboration, 74The CLAS Collaboration, 75The CLAS Collaboration, 76The CLAS Collaboration, 77The CLAS Collaboration, 78The CLAS Collaboration, 79The CLAS Collaboration, 80The CLAS Collaboration, 81The CLAS Collaboration, 82The CLAS Collaboration, 83The CLAS Collaboration, 84The CLAS Collaboration, 85The CLAS Collaboration, 86The CLAS Collaboration, 87The CLAS Collaboration, 88The CLAS Collaboration, 89The CLAS Collaboration, 90The CLAS Collaboration, 91The CLAS Collaboration, 92The CLAS Collaboration, 93The CLAS Collaboration, 94The CLAS Collaboration, 95The CLAS Collaboration, 96The CLAS Collaboration, 97The CLAS Collaboration, 98The CLAS Collaboration, 99The CLAS Collaboration, 100The CLAS Collaboration, 101The CLAS Collaboration, 102The CLAS Collaboration, 103The CLAS Collaboration, 104The CLAS Collaboration, 105The CLAS Collaboration, 106The CLAS Collaboration, 107The CLAS Collaboration, 108The CLAS Collaboration, 109The CLAS Collaboration, 110The CLAS Collaboration, 111The CLAS Collaboration, 112The CLAS Collaboration, 113The CLAS Collaboration, 114The CLAS Collaboration, 115The CLAS Collaboration, 116The CLAS Collaboration, 117The CLAS Collaboration, 118The CLAS Collaboration, 119The CLAS Collaboration, 120The CLAS Collaboration, 121The CLAS Collaboration, 122The CLAS Collaboration, 123The CLAS Collaboration, 124The CLAS Collaboration, 125The CLAS Collaboration, 126The CLAS Collaboration, 127The CLAS Collaboration, 128The CLAS Collaboration, 129The CLAS Collaboration, 130The CLAS Collaboration, 131The CLAS Collaboration, 132The CLAS Collaboration, 133The CLAS Collaboration, 134The CLAS Collaboration, 135The CLAS Collaboration, 136The CLAS Collaboration, 137The CLAS Collaboration, 138The CLAS Collaboration, 139The CLAS Collaboration, 140The CLAS Collaboration, 141The CLAS Collaboration, 142The CLAS Collaboration, 143The CLAS Collaboration, 144The CLAS Collaboration, 145The CLAS Collaboration, 146The CLAS Collaboration, 147The CLAS Collaboration, 148The CLAS Collaboration, 149The CLAS Collaboration, 150The CLAS Collaboration, 151The CLAS Collaboration, 152The CLAS Collaboration, 153The CLAS Collaboration, 154The CLAS Collaboration, 155The CLAS Collaboration, 156The CLAS Collaboration

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^0$ electroproduction reaction $\gamma^* p \to p \pi^0$, expanding an analysis of the $\gamma^* p \to n \pi^+$ 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. Read More

The charge and magnetic form factors, FC and FM, of 3He have been extracted in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering by detecting 3He recoil nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements are indicative of a second diffraction minimum for the magnetic form factor, which was predicted in the Q2 range of this experiment, and of a continuing diffractive structure for the charge form factor. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem. Read More

We propose to measure the photo-production cross section of $J/{\psi}$ near threshold, in search of the recently observed LHCb hidden-charm resonances $P_c$(4380) and $P_c$(4450) consistent with 'pentaquarks'. The observation of these resonances in photo-production will provide strong evidence of the true resonance nature of the LHCb states, distinguishing them from kinematic enhancements. A bremsstrahlung photon beam produced with an 11 GeV electron beam at CEBAF covers the energy range of $J/{\psi}$ production from the threshold photo-production energy of 8. Read More

2016Jul
Authors: P. E. Bosted1, M. J. Amaryan2, S. Anefalos Pereira3, H. Avakian4, R. A. Badui5, J. Ball6, N. A. Baltzell7, M. Battaglieri8, V. Batourine9, I. Bedlinskiy10, A. S. Biselli11, W. J. Briscoe12, S. Bültmann13, V. D. Burkert14, D. S. Carman15, A. Celentano16, S. Chandavar17, G. Charles18, L. Clark19, L. Colaneri20, P. L. Cole21, M. Contalbrigo22, V. Crede23, A. D'Angelo24, R. De Vita25, A. Deur26, E. De Sanctis27, C. Djalali28, R. Dupre29, H. Egiyan30, A. El Alaoui31, L. El Fassi32, L. Elouadrhiri33, P. Eugenio34, E. Fanchini35, G. Fedotov36, A. Filippi37, J. A. Fleming38, T. Forest39, A. Fradi40, N. Gevorgyan41, G. P. Gilfoyle42, F. X. Girod43, C. Gleason44, W. Gohn45, E. Golovatch46, R. W. Gothe47, K. A. Griffioen48, M. Guidal49, H. Hakobyan50, M. Hattawy51, K. Hicks52, M. Holtrop53, S. M. Hughes54, Y. Ilieva55, D. G. Ireland56, B. S. Ishkhanov57, E. L. Isupov58, H. Jiang59, H. S. Jo60, K. Joo61, S. Joosten62, G. Khachatryan63, M. Khandaker64, A. Kim65, W. Kim66, F. J. Klein67, S. Koirala68, V. Kubarovsky69, S. E. Kuhn70, L. Lanza71, L. A. Net72, P. Lenisa73, K. Livingston74, I. J. D. MacGregor75, M. E. McCracken76, B. McKinnon77, C. A. Meyer78, M. Mirazita79, V. I. Mokeev80, R. A. Montgomery81, E. Munevar82, C. Munoz Camacho83, G. Murdoch84, P. Nadel-Turonski85, S. Niccolai86, M. Osipenko87, A. I. Ostrovidov88, K. Park89, E. Pasyuk90, P. Peng91, W. Phelps92, S. Pisano93, O. Pogorelko94, J. W. Price95, Y. Prok96, D. Protopopescu97, B. A. Raue98, M. Ripani99, G. Rosner100, P. Rossi101, R. A. Schumacher102, Iu. Skorodumina103, G. D. Smith104, D. Sokhan105, N. Sparveris106, I. Stankovic107, I. I. Strakovsky108, S. Strauch109, M. Taiuti110, B. Torayev111, M. Ungaro112, H. Voskanyan113, E. Voutier114, X. Wei115, L. B. Weinstein116, J. Zhang117, I. Zonta118
Affiliations: 1CLAS Collaboration, 2CLAS Collaboration, 3CLAS Collaboration, 4CLAS Collaboration, 5CLAS Collaboration, 6CLAS Collaboration, 7CLAS Collaboration, 8CLAS Collaboration, 9CLAS Collaboration, 10CLAS Collaboration, 11CLAS Collaboration, 12CLAS Collaboration, 13CLAS Collaboration, 14CLAS Collaboration, 15CLAS Collaboration, 16CLAS Collaboration, 17CLAS Collaboration, 18CLAS Collaboration, 19CLAS Collaboration, 20CLAS Collaboration, 21CLAS Collaboration, 22CLAS Collaboration, 23CLAS Collaboration, 24CLAS Collaboration, 25CLAS Collaboration, 26CLAS Collaboration, 27CLAS Collaboration, 28CLAS Collaboration, 29CLAS Collaboration, 30CLAS Collaboration, 31CLAS Collaboration, 32CLAS Collaboration, 33CLAS Collaboration, 34CLAS Collaboration, 35CLAS Collaboration, 36CLAS Collaboration, 37CLAS Collaboration, 38CLAS Collaboration, 39CLAS Collaboration, 40CLAS Collaboration, 41CLAS Collaboration, 42CLAS Collaboration, 43CLAS Collaboration, 44CLAS Collaboration, 45CLAS Collaboration, 46CLAS Collaboration, 47CLAS Collaboration, 48CLAS Collaboration, 49CLAS Collaboration, 50CLAS Collaboration, 51CLAS Collaboration, 52CLAS Collaboration, 53CLAS Collaboration, 54CLAS Collaboration, 55CLAS Collaboration, 56CLAS Collaboration, 57CLAS Collaboration, 58CLAS Collaboration, 59CLAS Collaboration, 60CLAS Collaboration, 61CLAS Collaboration, 62CLAS Collaboration, 63CLAS Collaboration, 64CLAS Collaboration, 65CLAS Collaboration, 66CLAS Collaboration, 67CLAS Collaboration, 68CLAS Collaboration, 69CLAS Collaboration, 70CLAS Collaboration, 71CLAS Collaboration, 72CLAS Collaboration, 73CLAS Collaboration, 74CLAS Collaboration, 75CLAS Collaboration, 76CLAS Collaboration, 77CLAS Collaboration, 78CLAS Collaboration, 79CLAS Collaboration, 80CLAS Collaboration, 81CLAS Collaboration, 82CLAS Collaboration, 83CLAS Collaboration, 84CLAS Collaboration, 85CLAS Collaboration, 86CLAS Collaboration, 87CLAS Collaboration, 88CLAS Collaboration, 89CLAS Collaboration, 90CLAS Collaboration, 91CLAS Collaboration, 92CLAS Collaboration, 93CLAS Collaboration, 94CLAS Collaboration, 95CLAS Collaboration, 96CLAS Collaboration, 97CLAS Collaboration, 98CLAS Collaboration, 99CLAS Collaboration, 100CLAS Collaboration, 101CLAS Collaboration, 102CLAS Collaboration, 103CLAS Collaboration, 104CLAS Collaboration, 105CLAS Collaboration, 106CLAS Collaboration, 107CLAS Collaboration, 108CLAS Collaboration, 109CLAS Collaboration, 110CLAS Collaboration, 111CLAS Collaboration, 112CLAS Collaboration, 113CLAS Collaboration, 114CLAS Collaboration, 115CLAS Collaboration, 116CLAS Collaboration, 117CLAS Collaboration, 118CLAS Collaboration

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^+$ electroproduction reaction $\gamma^* p \to n \pi^+$. 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. Read More

2016Jul
Authors: X. Zheng1, K. P. Adhikari2, P. Bosted3, A. Deur4, V. Drozdov5, L. El Fassi6, Hyekoo Kang7, K. Kovacs8, S. Kuhn9, E. Long10, S. K. Phillips11, M. Ripani12, K. Slifer13, L. C. Smith14, D. Adikaram15, Z. Akbar16, M. J. Amaryan17, S. Anefalos Pereira18, G. Asryan19, H. Avakian20, R. A. Badui21, J. Ball22, N. A. Baltzell23, M. Battaglieri24, V. Batourine25, I. Bedlinskiy26, A. S. Biselli27, W. J. Briscoe28, S. Bültmann29, V. D. Burkert30, D. S. Carman31, A. Celentano32, S. Chandavar33, G. Charles34, J. -P. Chen35, T. Chetry36, Seonho Choi37, G. Ciullo38, L. Clark39, L. Colaneri40, P. L. Cole41, N. Compton42, M. Contalbrigo43, V. Crede44, A. D'Angelo45, N. Dashyan46, R. De Vita47, E. De Sanctis48, C. Djalali49, G. E. Dodge50, R. Dupre51, H. Egiyan52, A. El Alaoui53, L. Elouadrhiri54, P. Eugenio55, E. Fanchini56, G. Fedotov57, R. Fersch58, A. Filippi59, J. A. Fleming60, N. Gevorgyan61, Y. Ghandilyan62, G. P. Gilfoyle63, K. L. Giovanetti64, F. X. Girod65, C. Gleason66, E. Golovach67, R. W. Gothe68, K. A. Griffioen69, M. Guidal70, N. Guler71, L. Guo72, C. Hanretty73, N. Harrison74, M. Hattawy75, K. Hicks76, M. Holtrop77, S. M. Hughes78, Y. Ilieva79, D. G. Ireland80, B. S. Ishkhanov81, E. L. Isupov82, D. Jenkins83, H. Jiang84, H. S. Jo85, S. Joosten86, D. Keller87, G. Khachatryan88, M. Khandaker89, A. Kim90, W. Kim91, F. J. Klein92, V. Kubarovsky93, L. Lanza94, P. Lenisa95, K. Livingston96, I . J . D. MacGregor97, N. Markov98, B. McKinnon99, M. Mirazita100, V. Mokeev101, A. Movsisyan102, E. Munevar103, C. Munoz Camacho104, G. Murdoch105, P. Nadel-Turonski106, L. A. Net107, A. Ni108, S. Niccolai109, G. Niculescu110, I. Niculescu111, M. Osipenko112, A. I. Ostrovidov113, M. Paolone114, R. Paremuzyan115, K. Park116, E. Pasyuk117, P. Peng118, S. Pisano119, O. Pogorelko120, J. W. Price121, A. J. R. Puckett122, B. A. Raue123, A. Rizzo124, G. Rosner125, P. Rossi126, P. Roy127, F. Sabatié128, C. Salgado129, R. A. Schumacher130, Y. G. Sharabian131, Iu. Skorodumina132, G. D. Smith133, D. Sokhan134, N. Sparveris135, I. Stankovic136, I. I. Strakovsky137, S. Strauch138, M. Taiuti139, Ye Tian140, M. Ungaro141, H. Voskanyan142, E. Voutier143, N. K. Walford144, D. P. Watts145, X. Wei146, L. B. Weinstein147, M. H. Wood148, N. Zachariou149, J. Zhang150
Affiliations: 1The CLAS Collaboration, 2The CLAS Collaboration, 3The CLAS Collaboration, 4The CLAS Collaboration, 5The CLAS Collaboration, 6The CLAS Collaboration, 7The CLAS Collaboration, 8The CLAS Collaboration, 9The CLAS Collaboration, 10The CLAS Collaboration, 11The CLAS Collaboration, 12The CLAS Collaboration, 13The CLAS Collaboration, 14The CLAS Collaboration, 15The CLAS Collaboration, 16The CLAS Collaboration, 17The CLAS Collaboration, 18The CLAS Collaboration, 19The CLAS Collaboration, 20The CLAS Collaboration, 21The CLAS Collaboration, 22The CLAS Collaboration, 23The CLAS Collaboration, 24The CLAS Collaboration, 25The CLAS Collaboration, 26The CLAS Collaboration, 27The CLAS Collaboration, 28The CLAS Collaboration, 29The CLAS Collaboration, 30The CLAS Collaboration, 31The CLAS Collaboration, 32The CLAS Collaboration, 33The CLAS Collaboration, 34The CLAS Collaboration, 35The CLAS Collaboration, 36The CLAS Collaboration, 37The CLAS Collaboration, 38The CLAS Collaboration, 39The CLAS Collaboration, 40The CLAS Collaboration, 41The CLAS Collaboration, 42The CLAS Collaboration, 43The CLAS Collaboration, 44The CLAS Collaboration, 45The CLAS Collaboration, 46The CLAS Collaboration, 47The CLAS Collaboration, 48The CLAS Collaboration, 49The CLAS Collaboration, 50The CLAS Collaboration, 51The CLAS Collaboration, 52The CLAS Collaboration, 53The CLAS Collaboration, 54The CLAS Collaboration, 55The CLAS Collaboration, 56The CLAS Collaboration, 57The CLAS Collaboration, 58The CLAS Collaboration, 59The CLAS Collaboration, 60The CLAS Collaboration, 61The CLAS Collaboration, 62The CLAS Collaboration, 63The CLAS Collaboration, 64The CLAS Collaboration, 65The CLAS Collaboration, 66The CLAS Collaboration, 67The CLAS Collaboration, 68The CLAS Collaboration, 69The CLAS Collaboration, 70The CLAS Collaboration, 71The CLAS Collaboration, 72The CLAS Collaboration, 73The CLAS Collaboration, 74The CLAS Collaboration, 75The CLAS Collaboration, 76The CLAS Collaboration, 77The CLAS Collaboration, 78The CLAS Collaboration, 79The CLAS Collaboration, 80The CLAS Collaboration, 81The CLAS Collaboration, 82The CLAS Collaboration, 83The CLAS Collaboration, 84The CLAS Collaboration, 85The CLAS Collaboration, 86The CLAS Collaboration, 87The CLAS Collaboration, 88The CLAS Collaboration, 89The CLAS Collaboration, 90The CLAS Collaboration, 91The CLAS Collaboration, 92The CLAS Collaboration, 93The CLAS Collaboration, 94The CLAS Collaboration, 95The CLAS Collaboration, 96The CLAS Collaboration, 97The CLAS Collaboration, 98The CLAS Collaboration, 99The CLAS Collaboration, 100The CLAS Collaboration, 101The CLAS Collaboration, 102The CLAS Collaboration, 103The CLAS Collaboration, 104The CLAS Collaboration, 105The CLAS Collaboration, 106The CLAS Collaboration, 107The CLAS Collaboration, 108The CLAS Collaboration, 109The CLAS Collaboration, 110The CLAS Collaboration, 111The CLAS Collaboration, 112The CLAS Collaboration, 113The CLAS Collaboration, 114The CLAS Collaboration, 115The CLAS Collaboration, 116The CLAS Collaboration, 117The CLAS Collaboration, 118The CLAS Collaboration, 119The CLAS Collaboration, 120The CLAS Collaboration, 121The CLAS Collaboration, 122The CLAS Collaboration, 123The CLAS Collaboration, 124The CLAS Collaboration, 125The CLAS Collaboration, 126The CLAS Collaboration, 127The CLAS Collaboration, 128The CLAS Collaboration, 129The CLAS Collaboration, 130The CLAS Collaboration, 131The CLAS Collaboration, 132The CLAS Collaboration, 133The CLAS Collaboration, 134The CLAS Collaboration, 135The CLAS Collaboration, 136The CLAS Collaboration, 137The CLAS Collaboration, 138The CLAS Collaboration, 139The CLAS Collaboration, 140The CLAS Collaboration, 141The CLAS Collaboration, 142The CLAS Collaboration, 143The CLAS Collaboration, 144The CLAS Collaboration, 145The CLAS Collaboration, 146The CLAS Collaboration, 147The CLAS Collaboration, 148The CLAS Collaboration, 149The CLAS Collaboration, 150The CLAS Collaboration

We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1. Read More

2016Apr
Authors: P. E. Bosted1, A. S. Biselli2, S. Careccia3, G. Dodge4, R. Fersch5, S. E. Kuhn6, J. Pierce7, Y. Prok8, X. Zheng9, K. P. Adhikari10, D. Adikaram11, Z. Akbar12, M. J. Amaryan13, S. Anefalos Pereira14, G. Asryan15, H. Avakian16, R. A. Badui17, J. Ball18, N. A. Baltzell19, M. Battaglieri20, V. Batourine21, I. Bedlinskiy22, S. Boiarinov23, W. J. Briscoe24, S. Bültmann25, V. D. Burkert26, T. Cao27, D. S. Carman28, A. Celentano29, S. Chandavar30, G. Charles31, T. Chetry32, G. Ciullo33, L. Clark34, L. Colaneri35, P. L. Cole36, M. Contalbrigo37, O. Cortes38, V. Crede39, A. D'Angelo40, N. Dashyan41, R. De Vita42, A. Deur43, C. Djalali44, R. Dupre45, H. Egiyan46, A. El Alaoui47, L. El Fassi48, P. Eugenio49, E. Fanchini50, G. Fedotov51, A. Filippi52, J. A. Fleming53, T. A. Forest54, A. Fradi55, M. Garçon56, N. Gevorgyan57, Y. Ghandilyan58, G. P. Gilfoyle59, K. L. Giovanetti60, F. X. Girod61, C. Gleason62, W. Gohn63, E. Golovatch64, R. W. Gothe65, K. A. Griffioen66, N. Guler67, L. Guo68, K. Hafidi69, C. Hanretty70, N. Harrison71, M. Hattawy72, D. Heddle73, K. Hicks74, M. Holtrop75, S. M. Hughes76, Y. Ilieva77, D. G. Ireland78, B. S. Ishkhanov79, E. L. Isupov80, D. Jenkins81, H. Jiang82, H. S. Jo83, K. Joo84, S. Joosten85, D. Keller86, M. Khandaker87, W. Kim88, A. Klein89, F. J. Klein90, V. Kubarovsky91, S. V. Kuleshov92, L. Lanza93, P. Lenisa94, K. Livingston95, H. Y. Lu96, I . J . D. MacGregor97, N. Markov98, M. E. McCracken99, B. McKinnon100, C. A. Meyer101, R. Minehart102, M. Mirazita103, V. Mokeev104, A Movsisyan105, E. Munevar106, C. Munoz Camacho107, P. Nadel-Turonski108, L. A. Net109, A. Ni110, S. Niccolai111, G. Niculescu112, I. Niculescu113, M. Osipenko114, A. I. Ostrovidov115, R. Paremuzyan116, K. Park117, E. Pasyuk118, P. Peng119, W. Phelps120, S. Pisano121, O. Pogorelko122, J. W. Price123, S. Procureur124, D. Protopopescu125, A. J. R. Puckett126, B. A. Raue127, M. Ripani128, A. Rizzo129, G. Rosner130, P. Rossi131, P. Roy132, F. Sabatié133, C. Salgado134, R. A. Schumacher135, E. Seder136, Y. G. Sharabian137, A. Simonyan138, Iu. Skorodumina139, G. D. Smith140, N. Sparveris141, Ivana Stankovic142, S. Stepanyan143, I. I. Strakovsky144, S. Strauch145, V. Sytnik146, M. Taiuti147, Ye Tian148, B. Torayev149, M. Ungaro150, H. Voskanyan151, E. Voutier152, N. K. Walford153, D. P. Watts154, X. Wei155, L. B. Weinstein156, M. H. Wood157, N. Zachariou158, L. Zana159, J. Zhang160, Z. W. Zhao161, I. Zonta162
Affiliations: 1CLAS Collaboration, 2CLAS Collaboration, 3CLAS Collaboration, 4CLAS Collaboration, 5CLAS Collaboration, 6CLAS Collaboration, 7CLAS Collaboration, 8CLAS Collaboration, 9CLAS Collaboration, 10CLAS Collaboration, 11CLAS Collaboration, 12CLAS Collaboration, 13CLAS Collaboration, 14CLAS Collaboration, 15CLAS Collaboration, 16CLAS Collaboration, 17CLAS Collaboration, 18CLAS Collaboration, 19CLAS Collaboration, 20CLAS Collaboration, 21CLAS Collaboration, 22CLAS Collaboration, 23CLAS Collaboration, 24CLAS Collaboration, 25CLAS Collaboration, 26CLAS Collaboration, 27CLAS Collaboration, 28CLAS Collaboration, 29CLAS Collaboration, 30CLAS Collaboration, 31CLAS Collaboration, 32CLAS Collaboration, 33CLAS Collaboration, 34CLAS Collaboration, 35CLAS Collaboration, 36CLAS Collaboration, 37CLAS Collaboration, 38CLAS Collaboration, 39CLAS Collaboration, 40CLAS Collaboration, 41CLAS Collaboration, 42CLAS Collaboration, 43CLAS Collaboration, 44CLAS Collaboration, 45CLAS Collaboration, 46CLAS Collaboration, 47CLAS Collaboration, 48CLAS Collaboration, 49CLAS Collaboration, 50CLAS Collaboration, 51CLAS Collaboration, 52CLAS Collaboration, 53CLAS Collaboration, 54CLAS Collaboration, 55CLAS Collaboration, 56CLAS Collaboration, 57CLAS Collaboration, 58CLAS Collaboration, 59CLAS Collaboration, 60CLAS Collaboration, 61CLAS Collaboration, 62CLAS Collaboration, 63CLAS Collaboration, 64CLAS Collaboration, 65CLAS Collaboration, 66CLAS Collaboration, 67CLAS Collaboration, 68CLAS Collaboration, 69CLAS Collaboration, 70CLAS Collaboration, 71CLAS Collaboration, 72CLAS Collaboration, 73CLAS Collaboration, 74CLAS Collaboration, 75CLAS Collaboration, 76CLAS Collaboration, 77CLAS Collaboration, 78CLAS Collaboration, 79CLAS Collaboration, 80CLAS Collaboration, 81CLAS Collaboration, 82CLAS Collaboration, 83CLAS Collaboration, 84CLAS Collaboration, 85CLAS Collaboration, 86CLAS Collaboration, 87CLAS Collaboration, 88CLAS Collaboration, 89CLAS Collaboration, 90CLAS Collaboration, 91CLAS Collaboration, 92CLAS Collaboration, 93CLAS Collaboration, 94CLAS Collaboration, 95CLAS Collaboration, 96CLAS Collaboration, 97CLAS Collaboration, 98CLAS Collaboration, 99CLAS Collaboration, 100CLAS Collaboration, 101CLAS Collaboration, 102CLAS Collaboration, 103CLAS Collaboration, 104CLAS Collaboration, 105CLAS Collaboration, 106CLAS Collaboration, 107CLAS Collaboration, 108CLAS Collaboration, 109CLAS Collaboration, 110CLAS Collaboration, 111CLAS Collaboration, 112CLAS Collaboration, 113CLAS Collaboration, 114CLAS Collaboration, 115CLAS Collaboration, 116CLAS Collaboration, 117CLAS Collaboration, 118CLAS Collaboration, 119CLAS Collaboration, 120CLAS Collaboration, 121CLAS Collaboration, 122CLAS Collaboration, 123CLAS Collaboration, 124CLAS Collaboration, 125CLAS Collaboration, 126CLAS Collaboration, 127CLAS Collaboration, 128CLAS Collaboration, 129CLAS Collaboration, 130CLAS Collaboration, 131CLAS Collaboration, 132CLAS Collaboration, 133CLAS Collaboration, 134CLAS Collaboration, 135CLAS Collaboration, 136CLAS Collaboration, 137CLAS Collaboration, 138CLAS Collaboration, 139CLAS Collaboration, 140CLAS Collaboration, 141CLAS Collaboration, 142CLAS Collaboration, 143CLAS Collaboration, 144CLAS Collaboration, 145CLAS Collaboration, 146CLAS Collaboration, 147CLAS Collaboration, 148CLAS Collaboration, 149CLAS Collaboration, 150CLAS Collaboration, 151CLAS Collaboration, 152CLAS Collaboration, 153CLAS Collaboration, 154CLAS Collaboration, 155CLAS Collaboration, 156CLAS Collaboration, 157CLAS Collaboration, 158CLAS Collaboration, 159CLAS Collaboration, 160CLAS Collaboration, 161CLAS Collaboration, 162CLAS Collaboration

Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $\pi^+$ and $\pi^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $\pi^+$) and deuterons (for $\pi^-$) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Read More

2016Mar
Authors: D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, R. A. Badui, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, R. P. Bennett, A. S. Biselli, S. Boiarinov, W. J. Briscoe, S. Bültmann, D. S. Carman, A. Celentano, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, J. A. Fleming, T. A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, C. Gleason, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, L. Guo, K. Hafidi, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, S. Joosten, D. Keller, P. Khetarpal, G. Khachatryan, M. Khandaker, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, S. E. Kuhn, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, H. Y. Lu, I . J . D. MacGregor, N. Markov, B. McKinnon, M. D. Mestayer, M. Mirazita, V. Mokeev, A Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, A. Ni, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, A. J. R. Puckett, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatié, C. Salgado, R. A. Schumacher, E. Seder, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, Ivana Stankovic, S. Stepanyan, S. Strauch, V. Sytnik, M. Taiuti, B. Torayev, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta

[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 ($Q^{2}$). 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. Read More

2015Nov
Authors: A. Kim, H. Avakian, V. Burkert, K. Joo, W. Kim, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, R. A. Badui, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, P. Bosted, W. J. Briscoe, W. K. Brooks, S. Bültmann, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, C. Djalali, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, J. A. Fleming, A. Fradi, M. Garçon, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, L. Guo, K. Hafidi, C. Hanretty, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, D. Jenkins, H. Jiang, H. S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khandaker, A. Klein, F. J. Klein, V. Kubarovsky, S. E. Kuhn, S. V. Kuleshov, L. Lanza, P. Lenisa, H. Y. Lu, I . J . D. MacGregor, N. Markov, P. Mattione, M. E. McCracken, B. McKinnon, V. Mokeev, A Movsisyan, E. Munevar, P. Nadel-Turonski, L. A. Net, S. Niccolai, M. Osipenko, A. I. Ostrovidov, M. Paolone, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, C. Salgado, R. A. Schumacher, E. Seder, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, P. Stoler, I. I. Strakovsky, S. Strauch, V. Sytnik, M. Taiuti, B. Torayev, M. Ungaro, H. Voskanyan, E. Voutier, D. P. Watts, X. Wei, L. B. Weinstein, N. Zachariou, L. Zana, J. Zhang, I. Zonta

The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep\pi^0$ 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 $\phi$. Read More

We report on new p$(e,e^\prime p)\pi^\circ$ measurements at the $\Delta^{+}(1232)$ resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low $Q^2$ dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. Read More

2015Jul
Authors: M. E. McCracken, M. Bellis, K. P. Adhikari, D. Adikaram, Z. Akbar, S. Anefalos Pereira, R. A. Badui, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, W. J. Briscoe, W. K. Brooks, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P. L. Cole, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, G. E. Dodge, R. Dupre, A. El Alaoui, L. El Fassi, E. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, R. Fersch, A. Filippi, J. A. Fleming, B. Garillon, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, M. Hattawy, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, H. S. Jo, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, P. Lenisa, K. Livingston, H. Y. Lu, I. J. D. MacGregor, M. Mayer, B. McKinnon, M. D. Mestayer, C. A. Meyer, M. Mirazita, V. Mokeev, C. I. Moody, K. Moriya, C. Munoz Camacho, P. Nadel-Turonski, L. A. Net, S. Niccolai, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, S. Pisano, O. Pogorelko, J. W. Price, S. Procureur, Y. Prok, B. A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, R. A. Schumacher, E. Seder, Y. G. Sharabian, Iu. Skorodumina, D. Sokhan, N. Sparveris, P. Stoler, I. I. Strakovsky, S. Strauch, V. Sytnik, Ye Tian, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta

We present a search for ten baryon-number violating decay modes of $\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state ($\Lambda \rightarrow m \ell$) and conserve either the sum or the difference of baryon and lepton number ($B \pm L$). The tenth decay mode ($\Lambda \rightarrow \bar{p}\pi^+$) represents a difference in baryon number of two units and no difference in lepton number. Read More

2015Jul
Authors: I. Senderovich, B. T. Morrison, M. Dugger, B. G. Ritchie, E. Pasyuk, R. Tucker, J. Brock, C. Carlin, C. D. Keith, D. G. Meekins, M. L. Seely, D. R, M. D, P. Collins, K. P. Adhikari, D. Adikaram, Z. Akbar, M. D. Anderson, S. Anefalos Pereira, R. A. Badui, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, W. J. Briscoe, W. K. Brooks, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P. L. Cole, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, A. Fradi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J. A. Fleming, B. Garillon, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. -X. Girod, D. I. Glazier, J. T. Goetz, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, D. Jenkins, H. Jiang, H. S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, F. J. Klein, V. Kubarovsky, M. C. Kunkel, P. Lenisa, K. Livingston, H. Y. Lu, I. J. D. MacGregor, P. Mattione, B. McKinnon, C. A. Meyer, T. Mineeva, V. Mokeev, R. A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L. A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, K. Park, S. Park, P. Peng, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, A. J. R. Puckett, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatie, C. Salgado, D. Schott, R. A. Schumacher, E. Seder, A. Simonyan, Iu. Skorodumina, G. D. Smith, D. I. Sober, D. Sokhan, N. Sparveris, S. Stepanyan, P. Stoler, I. I. Strakovsky, S. Strauch, V. Sytnik, Ye Tian, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, X. Wei, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta

Results are presented for the first measurement of the double-polarization helicity asymmetry E for the $\eta$ photoproduction reaction $\gamma p \rightarrow \eta p$. 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. Read More

2015May
Authors: N. Guler, R. G. Fersch, S. E. Kuhn, P. Bosted, K. A. Griffioen, C. Keith, R. Minehart, Y. Prok, K. P. Adhikari, D. Adikaram, M. J. Amaryan, M. D. Anderson, S. Anefalos Pereira, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, W. J. Briscoe, W. K. Brooks, S. Bultmann, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P. L. Cole, M. Contalbrigo, D. Crabb, V. Crede, A. D Angelo, N. Dashyan, A. Deur, C. Djalali, G. E. Dodge, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J. A. Fleming, T. A. Forest, B. Garillon, M. Garcon, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, J. T. Goetz, E. Golovatch, R. W. Gothe, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S. M. Hughes, C. E. Hyde, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, H. S. Jo, K. Joo, S. Joosten, D. Keller, M. Khandaker, A. Kim, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, S. V. Kuleshov, K. Livingston, H. Y. Lu, I. J. D. MacGregor, B. McKinnon, M. Mirazita, V. Mokeev, R. A. Montgomery, A Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L. A. Net, I. Niculescu, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, S. Pisano, O. Pogorelko, J. W. Price, S. Procureur, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatie, C. Salgado, D. Schott, R. A. Schumacher, E. Seder, A. Simonyan, Iu. Skorodumina, D. Sokhan, N. Sparveris, I. I. Strakovsky, S. Strauch, V. Sytnik, Ye Tian, S. Tkachenko, M. Ungaro, E. Voutier, N. K. Walford, X. Wei, L. B. Weinstein, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta

We present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2. Read More

2015Mar
Authors: Nicholas Zachariou, Yordanka Ilieva, Nikolay Ya. Ivanov, Misak M Sargsian, Robert Avakian, Gerald Feldman, Pawel Nadel-Turonski, K. P. Adhikari, D. Adikaram, M. D. Anderson, S. Anefalos Pereira, H. Avakian, R. A. Badui, N. A. Baltzell, M. Battaglieri, V. Baturin, I. Bedlinskiy, A. S. Biselli, W. J. Briscoe, W. K. Brooks, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, G. Fedotov, S. Fegan, A. Filippi, J. A. Fleming, T. A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, D. I. Glazier, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, K. Hafidi, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S. M. Hughes, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, H. Jiang, H. S. Jo, K. Joo, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, W. Kim, F. J. Klein, V. Kubarovsky, P. Lenisa, K. Livingston, H. Y. Lu, I . J . D. MacGregor, N. Markov, P. T. Mattione, B. McKinnon, T. Mineeva, M. Mirazita, V. I. Mokeeev, R. A. Montgomery, H. Moutarde, C. Munoz Camacho, L. A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, W. Phelps, J. J. Phillips, S. Pisano, O. Pogorelko, S. Pozdniakov, J. W. Price, S. Procureur, Y. Prok, D. Protopopescu, A. J. R. Puckett, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatié, C. Salgado, D. Schott, R. A. Schumacher, E. Seder, I. Senderovich, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. I. Sober, D. Sokhan, N. Sparveris, S. Stepanyan, S. Strauch, V. Sytnik, M. Taiuti, Ye Tian, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, D. Watts, X. Wei, M. H. Wood, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta, for the CLAS collaboration

The beam-spin asymmetry, $\Sigma$, for the reaction $\gamma d\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $\theta_{c. Read More

2015Mar
Authors: S. Strauch1, W. J. Briscoe2, M. Döring3, E. Klempt4, V. A. Nikonov5, E. Pasyuk6, D. Rönchen7, A. V. Sarantsev8, I. Strakovsky9, R. Workman10, K. P. Adhikari11, D. Adikaram12, M. D. Anderson13, S. Anefalos Pereira14, A. V. Anisovich15, R. A. Badui16, J. Ball17, V. Batourine18, M. Battaglieri19, I. Bedlinskiy20, N. Benmouna21, A. S. Biselli22, J. Brock23, W. K. Brooks24, V. D. Burkert25, T. Cao26, C. Carlin27, D. S. Carman28, A. Celentano29, S. Chandavar30, G. Charles31, L. Colaneri32, P. L. Cole33, N. Compton34, M. Contalbrigo35, O. Cortes36, V. Crede37, N. Dashyan38, A. D'Angelo39, R. De Vita40, E. De Sanctis41, A. Deur42, C. Djalali43, M. Dugger44, R. Dupre45, H. Egiyan46, A. El Alaoui47, L. El Fassi48, L. Elouadrhiri49, P. Eugenio50, G. Fedotov51, S. Fegan52, A. Filippi53, J. A. Fleming54, T. A. Forest55, A. Fradi56, N. Gevorgyan57, Y. Ghandilyan58, K. L. Giovanetti59, F. X. Girod60, D. I. Glazier61, W. Gohn62, E. Golovatch63, R. W. Gothe64, K. A. Griffioen65, M. Guidal66, L. Guo67, K. Hafidi68, H. Hakobyan69, C. Hanretty70, N. Harrison71, M. Hattawy72, K. Hicks73, D. Ho74, M. Holtrop75, S. M. Hughes76, Y. Ilieva77, D. G. Ireland78, B. S. Ishkhanov79, E. L. Isupov80, D. Jenkins81, H. Jiang82, H. S. Jo83, K. Joo84, S. Joosten85, C. D. Keith86, D. Keller87, G. Khachatryan88, M. Khandaker89, A. Kim90, W. Kim91, A. Klein92, F. J. Klein93, V. Kubarovsky94, S. E. Kuhn95, P. Lenisa96, K. Livingston97, H. Y. Lu98, I . J . D. MacGregor99, N. Markov100, B. McKinnon101, D. G. Meekins102, C. A. Meyer103, V. Mokeev104, R. A. Montgomery105, C. I. Moody106, H. Moutarde107, A Movsisyan108, E. Munevar109, C. Munoz Camacho110, P. Nadel-Turonski111, L. A. Net112, S. Niccolai113, G. Niculescu114, I. Niculescu115, M. Osipenko116, A. I. Ostrovidov117, K. Park118, P. Peng119, W. Phelps120, J. J. Phillips121, S. Pisano122, O. Pogorelko123, S. Pozdniakov124, J. W. Price125, S. Procureur126, Y. Prok127, D. Protopopescu128, A. J. R. Puckett129, B. A. Raue130, M. Ripani131, B. G. Ritchie132, A. Rizzo133, G. Rosner134, P. Roy135, F. Sabatié136, C. Salgado137, D. Schott138, R. A. Schumacher139, E. Seder140, M. L. Seely141, I Senderovich142, Y. G. Sharabian143, A. Simonyan144, Iu. Skorodumina145, G. D. Smith146, D. I. Sober147, D. Sokhan148, N. Sparveris149, P. Stoler150, S. Stepanyan151, V. Sytnik152, M. Taiuti153, Ye Tian154, A. Trivedi155, R. Tucker156, M. Ungaro157, H. Voskanyan158, E. Voutier159, N. K. Walford160, D. P. Watts161, X. Wei162, M. H. Wood163, N. Zachariou164, L. Zana165, J. Zhang166, Z. W. Zhao167, I. Zonta168
Affiliations: 1The CLAS Collaboration, 2The CLAS Collaboration, 3The CLAS Collaboration, 4The CLAS Collaboration, 5The CLAS Collaboration, 6The CLAS Collaboration, 7The CLAS Collaboration, 8The CLAS Collaboration, 9The CLAS Collaboration, 10The CLAS Collaboration, 11The CLAS Collaboration, 12The CLAS Collaboration, 13The CLAS Collaboration, 14The CLAS Collaboration, 15The CLAS Collaboration, 16The CLAS Collaboration, 17The CLAS Collaboration, 18The CLAS Collaboration, 19The CLAS Collaboration, 20The CLAS Collaboration, 21The CLAS Collaboration, 22The CLAS Collaboration, 23The CLAS Collaboration, 24The CLAS Collaboration, 25The CLAS Collaboration, 26The CLAS Collaboration, 27The CLAS Collaboration, 28The CLAS Collaboration, 29The CLAS Collaboration, 30The CLAS Collaboration, 31The CLAS Collaboration, 32The CLAS Collaboration, 33The CLAS Collaboration, 34The CLAS Collaboration, 35The CLAS Collaboration, 36The CLAS Collaboration, 37The CLAS Collaboration, 38The CLAS Collaboration, 39The CLAS Collaboration, 40The CLAS Collaboration, 41The CLAS Collaboration, 42The CLAS Collaboration, 43The CLAS Collaboration, 44The CLAS Collaboration, 45The CLAS Collaboration, 46The CLAS Collaboration, 47The CLAS Collaboration, 48The CLAS Collaboration, 49The CLAS Collaboration, 50The CLAS Collaboration, 51The CLAS Collaboration, 52The CLAS Collaboration, 53The CLAS Collaboration, 54The CLAS Collaboration, 55The CLAS Collaboration, 56The CLAS Collaboration, 57The CLAS Collaboration, 58The CLAS Collaboration, 59The CLAS Collaboration, 60The CLAS Collaboration, 61The CLAS Collaboration, 62The CLAS Collaboration, 63The CLAS Collaboration, 64The CLAS Collaboration, 65The CLAS Collaboration, 66The CLAS Collaboration, 67The CLAS Collaboration, 68The CLAS Collaboration, 69The CLAS Collaboration, 70The CLAS Collaboration, 71The CLAS Collaboration, 72The CLAS Collaboration, 73The CLAS Collaboration, 74The CLAS Collaboration, 75The CLAS Collaboration, 76The CLAS Collaboration, 77The CLAS Collaboration, 78The CLAS Collaboration, 79The CLAS Collaboration, 80The CLAS Collaboration, 81The CLAS Collaboration, 82The CLAS Collaboration, 83The CLAS Collaboration, 84The CLAS Collaboration, 85The CLAS Collaboration, 86The CLAS Collaboration, 87The CLAS Collaboration, 88The CLAS Collaboration, 89The CLAS Collaboration, 90The CLAS Collaboration, 91The CLAS Collaboration, 92The CLAS Collaboration, 93The CLAS Collaboration, 94The CLAS Collaboration, 95The CLAS Collaboration, 96The CLAS Collaboration, 97The CLAS Collaboration, 98The CLAS Collaboration, 99The CLAS Collaboration, 100The CLAS Collaboration, 101The CLAS Collaboration, 102The CLAS Collaboration, 103The CLAS Collaboration, 104The CLAS Collaboration, 105The CLAS Collaboration, 106The CLAS Collaboration, 107The CLAS Collaboration, 108The CLAS Collaboration, 109The CLAS Collaboration, 110The CLAS Collaboration, 111The CLAS Collaboration, 112The CLAS Collaboration, 113The CLAS Collaboration, 114The CLAS Collaboration, 115The CLAS Collaboration, 116The CLAS Collaboration, 117The CLAS Collaboration, 118The CLAS Collaboration, 119The CLAS Collaboration, 120The CLAS Collaboration, 121The CLAS Collaboration, 122The CLAS Collaboration, 123The CLAS Collaboration, 124The CLAS Collaboration, 125The CLAS Collaboration, 126The CLAS Collaboration, 127The CLAS Collaboration, 128The CLAS Collaboration, 129The CLAS Collaboration, 130The CLAS Collaboration, 131The CLAS Collaboration, 132The CLAS Collaboration, 133The CLAS Collaboration, 134The CLAS Collaboration, 135The CLAS Collaboration, 136The CLAS Collaboration, 137The CLAS Collaboration, 138The CLAS Collaboration, 139The CLAS Collaboration, 140The CLAS Collaboration, 141The CLAS Collaboration, 142The CLAS Collaboration, 143The CLAS Collaboration, 144The CLAS Collaboration, 145The CLAS Collaboration, 146The CLAS Collaboration, 147The CLAS Collaboration, 148The CLAS Collaboration, 149The CLAS Collaboration, 150The CLAS Collaboration, 151The CLAS Collaboration, 152The CLAS Collaboration, 153The CLAS Collaboration, 154The CLAS Collaboration, 155The CLAS Collaboration, 156The CLAS Collaboration, 157The CLAS Collaboration, 158The CLAS Collaboration, 159The CLAS Collaboration, 160The CLAS Collaboration, 161The CLAS Collaboration, 162The CLAS Collaboration, 163The CLAS Collaboration, 164The CLAS Collaboration, 165The CLAS Collaboration, 166The CLAS Collaboration, 167The CLAS Collaboration, 168The CLAS Collaboration

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction $\vec \gamma \vec p \to \pi^+n$, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2. Read More

New results are reported from a measurement of $\pi^0$ electroproduction near threshold using the $p(e,e^{\prime} p)\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. Read More

2014Nov
Authors: D. Adikaram, D. Rimal, L. B. Weinstein, B. Raue, P. Khetarpal, R. P. Bennett, J. Arrington, W. K. Brooks, K. P. Adhikari, A. V. Afanasev, M. J. Amaryan, M. D. Anderson, J. Ball, M. Battaglieri, I. Bedlinskiy, A. S. Biselli, J. Bono, S. Boiarinov, W. J. Briscoe, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P. L. Cole, M. Contalbrigo, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, G. E. Dodge, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J. A. Fleming, A. Fradi, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, J. T. Goetz, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, K. Hicks, M. Holtrop, S. M. Hughes, C. E. Hyde, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, D. Jenkins, H. Jiang, K. Joo, S. Joosten, M. Khandaker, W. Kim, A. Klein, F. J. Klein, S. Koirala, V. Kubarovsky, S. E. Kuhn, H. Y. Lu, I . J . D. MacGregor, N. Markov, M. Mayer, B. McKinnon, M. D. Mestayer, C. A. Meyer, M. Mirazita, V. Mokeev, R. A. Montgomery, C. I. Moody, H. Moutarde, A Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, S. Pisano, O. Pogorelko, S. Procureur, Y. Prok, D. Protopopescu, A. J. R. Puckett, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, D. Schott, R. A. Schumacher, Y. G. Sharabian, A. Simonyan, I. Skorodumina, E. S. Smith, G. D. Smith, D. I. Sober, N. Sparveris, S. Stepanyan, S. Strauch, V. Sytnik, M. Taiuti, Ye Tian, A. Trivedi, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta, The CLAS Collaboration

There is a significant discrepancy between the values of the proton electric form factor, $G_E^p$, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of $G_E^p$ from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. Read More

2014Jan

We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Read More

The charge form factor of $^$4He has been extracted in the range 29 fm$^{-2}$ $\le Q^2 \le 77$ fm$^{-2}$ from elastic electron scattering, detecting $^4$He nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility of Jefferson Lab. The results are in qualitative agreement with realistic meson-nucleon theoretical calculations. The data have uncovered a second diffraction minimum, which was predicted in the $Q^2$ range of this experiment, and rule out conclusively long-standing predictions of dimensional scaling of high-energy amplitudes using quark counting. Read More

We report new p$(\vec{e},e^\prime p)\pi^\circ$ measurements in the $\Delta^{+}(1232)$ resonance at the low momentum transfer region utilizing the magnetic spectrometers of the A1 Collaboration at MAMI. The mesonic cloud dynamics are predicted to be dominant and appreciably changing in this region while the momentum transfer is sufficiently low to be able to test chiral effective calculations. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations with pion cloud effects, chiral effective field theory and lattice calculations. Read More

The study of the $\gamma^* N\rightarrow \Delta$ reaction presents the best quantitative method to explore the deviation of hadron shapes from spherical symmetry (nonspherical amplitudes). Significant non-spherical electric (E2) and Coulomb quadrupole (C2) amplitudes have been observed with good precision as a function of $Q^2$ from photon point up to $\approx 7 ~(GeV/c)^2$. Quark model calculations for these quadrupole amplitudes are at least an order of magnitude too small and even have the wrong sign. Read More

2013Mar
Authors: I. Pomerantz1, Y. Ilieva2, R. Gilman3, D. W. Higinbotham4, E. Piasetzky5, S. Strauch6, K. P. Adhikari7, M. Aghasyan8, K. Allada9, M. J. Amaryan10, S. Anefalos Pereira11, M. Anghinolfi12, H. Baghdasaryan13, J. Ball14, N. A. Baltzell15, M. Battaglieri16, V. Batourine17, A. Beck18, S. Beck19, I. Bedlinskiy20, B. L. Berman21, A. S. Biselli22, W. Boeglin23, J. Bono24, C. Bookwalter25, S. Boiarinov26, W. J. Briscoe27, W. K. Brooks28, N. Bubis29, V. Burkert30, A. Camsonne31, M. Canan32, D. S. Carman33, A. Celentano34, S. Chandavar35, G. Charles36, K. Chirapatpimol37, E. Cisbani38, P. L. Cole39, M. Contalbrigo40, V. Crede41, F. Cusanno42, A. D'Angelo43, A. Daniel44, N. Dashyan45, C. W. de Jager46, R. De Vita47, E. De Sanctis48, A. Deur49, C. Djalali50, G. E. Dodge51, D. Doughty52, R. Dupre53, C. Dutta54, H. Egiyan55, A. El Alaoui56, L. El Fassi57, P. Eugenio58, G. Fedotov59, S. Fegan60, J. A. Fleming61, A. Fradi62, F. Garibaldi63, O. Geagla64, N. Gevorgyan65, K. L. Giovanetti66, F. X. Girod67, J. Glister68, J. T. Goetz69, W. Gohn70, E. Golovatch71, R. W. Gothe72, K. A. Griffioen73, B. Guegan74, M. Guidal75, L. Guo76, K. Hafidi77, H. Hakobyan78, N. Harrison79, D. Heddle80, K. Hicks81, D. Ho82, M. Holtrop83, C. E. Hyde84, D. G. Ireland85, B. S. Ishkhanov86, E. L. Isupov87, X. Jiang88, H. S. Jo89, K. Joo90, A. T. Katramatou91, D. Keller92, M. Khandaker93, P. Khetarpal94, E. Khrosinkova95, A. Kim96, W. Kim97, F. J. Klein98, S. Koirala99, A. Kubarovsky100, V. Kubarovsky101, S. V. Kuleshov102, N. D. Kvaltine103, B. Lee104, J. J. LeRose105, S. Lewis106, R. Lindgren107, K. Livingston108, H. Y. Lu109, I. J. D. MacGregor110, Y. Mao111, D. Martinez112, M. Mayer113, E. McCullough114, B. McKinnon115, D. Meekins116, C. A. Meyer117, R. Michaels118, T. Mineeva119, M. Mirazita120, B. Moffit121, V. Mokeev122, R. A. Montgomery123, H. Moutarde124, E. Munevar125, C. Munoz Camacho126, P. Nadel-Turonski127, R. Nasseripour128, C. S. Nepali129, S. Niccolai130, G. Niculescu131, I. Niculescu132, M. Osipenko133, A. I. Ostrovidov134, L. L. Pappalardo135, R. Paremuzyan136, K. Park137, S. Park138, G. G. Petratos139, E. Phelps140, S. Pisano141, O. Pogorelko142, S. Pozdniakov143, S. Procureur144, D. Protopopescu145, A. J. R. Puckett146, X. Qian147, Y. Qiang148, G. Ricco149, D. Rimal150, M. Ripani151, B. G. Ritchie152, I. Rodriguez153, G. Ron154, G. Rosner155, P. Rossi156, F. Sabatie157, A. Saha158, M. S. Saini159, A. J. Sarty160, B. Sawatzky161, N. A. Saylor162, D. Schott163, E. Schulte164, R. A. Schumacher165, E. Seder166, H. Seraydaryan167, R. Shneor168, G. D. Smith169, D. Sokhan170, N. Sparveris171, S. S. Stepanyan172, S. Stepanyan173, P. Stoler174, R. Subedi175, V. Sulkosky176, M. Taiuti177, W. Tang178, C. E. Taylor179, S. Tkachenko180, M. Ungaro181, B. Vernarsky182, M. F. Vineyard183, H. Voskanyan184, E. Voutier185, N. K. Walford186, Y. Wang187, D. P. Watts188, L. B. Weinstein189, D. P. Weygand190, B. Wojtsekhowski191, M. H. Wood192, X. Yan193, H. Yao194, N. Zachariou195, X. Zhan196, J. Zhang197, Z. W. Zhao198, X. Zheng199, I. Zonta200
Affiliations: 1The CLAS and Hall-A Collaborations, 2The CLAS and Hall-A Collaborations, 3The CLAS and Hall-A Collaborations, 4The CLAS and Hall-A Collaborations, 5The CLAS and Hall-A Collaborations, 6The CLAS and Hall-A Collaborations, 7The CLAS and Hall-A Collaborations, 8The CLAS and Hall-A Collaborations, 9The CLAS and Hall-A Collaborations, 10The CLAS and Hall-A Collaborations, 11The CLAS and Hall-A Collaborations, 12The CLAS and Hall-A Collaborations, 13The CLAS and Hall-A Collaborations, 14The CLAS and Hall-A Collaborations, 15The CLAS and Hall-A Collaborations, 16The CLAS and Hall-A Collaborations, 17The CLAS and Hall-A Collaborations, 18The CLAS and Hall-A Collaborations, 19The CLAS and Hall-A Collaborations, 20The CLAS and Hall-A Collaborations, 21The CLAS and Hall-A Collaborations, 22The CLAS and Hall-A Collaborations, 23The CLAS and Hall-A Collaborations, 24The CLAS and Hall-A Collaborations, 25The CLAS and Hall-A Collaborations, 26The CLAS and Hall-A Collaborations, 27The CLAS and Hall-A Collaborations, 28The CLAS and Hall-A Collaborations, 29The CLAS and Hall-A Collaborations, 30The CLAS and Hall-A Collaborations, 31The CLAS and Hall-A Collaborations, 32The CLAS and Hall-A Collaborations, 33The CLAS and Hall-A Collaborations, 34The CLAS and Hall-A Collaborations, 35The CLAS and Hall-A Collaborations, 36The CLAS and Hall-A Collaborations, 37The CLAS and Hall-A Collaborations, 38The CLAS and Hall-A Collaborations, 39The CLAS and Hall-A Collaborations, 40The CLAS and Hall-A Collaborations, 41The CLAS and Hall-A Collaborations, 42The CLAS and Hall-A Collaborations, 43The CLAS and Hall-A Collaborations, 44The CLAS and Hall-A Collaborations, 45The CLAS and Hall-A Collaborations, 46The CLAS and Hall-A Collaborations, 47The CLAS and Hall-A Collaborations, 48The CLAS and Hall-A Collaborations, 49The CLAS and Hall-A Collaborations, 50The CLAS and Hall-A Collaborations, 51The CLAS and Hall-A Collaborations, 52The CLAS and Hall-A Collaborations, 53The CLAS and Hall-A Collaborations, 54The CLAS and Hall-A Collaborations, 55The CLAS and Hall-A Collaborations, 56The CLAS and Hall-A Collaborations, 57The CLAS and Hall-A Collaborations, 58The CLAS and Hall-A Collaborations, 59The CLAS and Hall-A Collaborations, 60The CLAS and Hall-A Collaborations, 61The CLAS and Hall-A Collaborations, 62The CLAS and Hall-A Collaborations, 63The CLAS and Hall-A Collaborations, 64The CLAS and Hall-A Collaborations, 65The CLAS and Hall-A Collaborations, 66The CLAS and Hall-A Collaborations, 67The CLAS and Hall-A Collaborations, 68The CLAS and Hall-A Collaborations, 69The CLAS and Hall-A Collaborations, 70The CLAS and Hall-A Collaborations, 71The CLAS and Hall-A Collaborations, 72The CLAS and Hall-A Collaborations, 73The CLAS and Hall-A Collaborations, 74The CLAS and Hall-A Collaborations, 75The CLAS and Hall-A Collaborations, 76The CLAS and Hall-A Collaborations, 77The CLAS and Hall-A Collaborations, 78The CLAS and Hall-A Collaborations, 79The CLAS and Hall-A 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We have measured cross sections for the gamma+3He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. Read More

The Proton Radius Puzzle is the inconsistency between the proton radius determined from muonic hydrogen and the proton radius determined from atomic hydrogen level transitions and ep elastic scattering. No generally accepted resolution to the Puzzle has been found. Possible solutions generally fall into one of three categories: the two radii are different due to novel beyond-standard-model physics, the two radii are different due to novel aspects of nucleon structure, and the two radii are the same, but there are underestimated uncertainties or other issues in the ep experiments. Read More

We report on new beam-helicity asymmetry measurements (A_h) of the H(\vec{e},e'p)\gamma reaction in the Delta(1232)$ resonance at Q2=0.20 (GeV/c)2. The measurements were performed at MAMI and were carried out simultaneously with the measurement of the H(\vec{e},e'p)\pi^0 reaction channel. Read More

We report new precision p(e,e' pi+})n measurements in the Delta(1232) resonance at Q2 = 0.127(GeV/c)2 obtained at the MIT-Bates Out-Of-Plane scattering facility. These are the lowest, but non-zero, Q2 measurements in the pi+ channel. Read More

We report on new H$(e,e^\prime p)\gamma$ measurements in the $\Delta(1232)$ resonance at $Q^2=0.06$ (GeV/c) carried out simultaneously with H$(e,e^\prime p)\pi^0$. It is the lowest $Q^2$ for which the virtual Compton scattering (VCS) reaction has been studied in the first resonance region. Read More

We report new precise p$(\vec{e},e^\prime p)\pi^0$ measurements at the peak of the $\Delta^{+}(1232)$ resonance at $Q^2=\unit[0.20](GeV/c)^2$ performed at the Mainz Microtron (MAMI). The new data are sensitive to both the electric quadrupole ($E2$) and the coulomb quadrupole ($C2$) amplitudes of the $\gamma^* N\to\Delta$ transition. Read More

The mean square polarizability radii of the proton have been measured for the first time in a virtual Compton scattering experiment performed at the MIT-Bates out-of-plane scattering facility. Response functions and polarizabilities obtained from a dispersion analysis of the data at Q2=0.06 GeV2/c2 are in agreement with O(p3) heavy baryon chiral perturbation theory. Read More

To determine nonspherical angular momentum amplitudes in hadrons at long ranges (low Q^2), data were taken for the p(\vec{e},e'p)\pi^0 reaction in the Delta region at Q^2=0.060 (GeV/c)^2 utilizing the magnetic spectrometers of the A1 Collaboration at MAMI. The results for the dominant transition magnetic dipole amplitude and the quadrupole to dipole ratios at W=1232 MeV are: M_{1+}^{3/2} = (40. Read More

We report new precise H$(e,e^\prime p)\pi^0$ measurements at the $\Delta(1232)$ resonance at $Q^2= 0.127$ (GeV/c)$^2$ using the MIT/Bates out-of-plane scattering (OOPS) facility. The data reported here are particularly sensitive to the transverse electric amplitude ($E2$) of the $\gamma^* N\to\Delta$ transition. Read More

2002Dec
Affiliations: 1OOPS Collaboration, 2OOPS Collaboration, 3OOPS Collaboration, 4OOPS Collaboration, 5OOPS Collaboration, 6OOPS Collaboration, 7OOPS Collaboration, 8OOPS Collaboration, 9OOPS Collaboration, 10OOPS Collaboration, 11OOPS Collaboration, 12OOPS Collaboration, 13OOPS Collaboration, 14OOPS Collaboration, 15OOPS Collaboration, 16OOPS Collaboration, 17OOPS Collaboration, 18OOPS Collaboration, 19OOPS Collaboration, 20OOPS Collaboration, 21OOPS Collaboration, 22OOPS Collaboration, 23OOPS Collaboration, 24OOPS Collaboration, 25OOPS Collaboration, 26OOPS Collaboration, 27OOPS Collaboration, 28OOPS Collaboration, 29OOPS Collaboration, 30OOPS Collaboration, 31OOPS Collaboration, 32OOPS Collaboration, 33OOPS Collaboration, 34OOPS Collaboration, 35OOPS Collaboration, 36OOPS Collaboration, 37OOPS Collaboration, 38OOPS Collaboration, 39OOPS Collaboration, 40OOPS Collaboration, 41OOPS Collaboration, 42OOPS Collaboration, 43OOPS Collaboration, 44OOPS Collaboration, 45OOPS Collaboration, 46OOPS Collaboration, 47OOPS Collaboration

Quadrupole amplitudes in the $\gamma^{*}N\to\Delta$ transition are associated with the issue of nucleon deformation. A search for these small amplitudes has been the focus of a series of measurements undertaken at Bates/MIT by the OOPS collaboration. We report on results from H$(e,e^\prime p)\pi^0$ data obtained at $Q^2= 0. Read More