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162 results on '"L. Elouadrhiri"'

1. A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime

Author

S. Diehl, A. Kim, K. Joo, P. Achenbach, Z. Akbar, M.J. Amaryan, H. Atac, H. Avagyan, C. Ayerbe Gayoso, L. Baashen, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, W.A. Booth, F. Bossù, S. Boiarinov, K.-Th. Brinkmann, W.J. Briscoe, S. Bueltmann, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, A. Filippi, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, D.I. Glazier, A.A. Golubenko, G. Gosta, R.W. Gothe, Y. Gotra, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, H.S. Jo, M. Khachatryan, A. Khanal, W. Kim, A. Kripko, V. Kubarovsky, V. Lagerquist, J.-M. Laget, L. Lanza, M. Leali, S. Lee, P. Lenisa, X. Li, K. Livingston, I. .J .D. MacGregor, D. Marchand, V. Mascagna, B. McKinnon, Z.E. Meziani, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, E. Molina, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, T. Reed, J. Richards, M. Ripani, J. Ritman, P. Rossi, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, Y. Sharabian, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, M. Spreafico, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Trotta, M. Turisini, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Williams, R. Wishart, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and M. Zurek

Subjects
Exclusive single pion, Eletroproduction, GPD, CLAS12, Physics, QC1-999
Abstract

A multidimensional extraction of the structure function ratio σLT′/σ0 from the hard exclusive e→p→e′nπ+ 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/Q2 ≪ 1) with a wide kinematic range of xB in the valence regime (0.17 < xB < 0.55), and virtualities Q2 ranging from 1.5 GeV2 up to 6 GeV2. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low Q2, while the GPD model is more appropriate at high Q2.

Published
2023
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2. 12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

Author

I. Korover, J.R. Pybus, A. Schmidt, F. Hauenstein, M. Duer, O. Hen, E. Piasetzky, L.B. Weinstein, D.W. Higinbotham, S. Adhikari, K. Adhikari, M.J. Amaryan, Giovanni Angelini, H. Atac, L. Barion, M. Battaglieri, A. Beck, I. Bedlinskiy, Fatiha Benmokhtar, A. Bianconi, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, L. Clark, B. Clary, P.L. Cole, M. Contalbrigo, V. Crede, R. Cruz-Torres, A. D'Angelo, R. De Vita, M. Defurne, A. Denniston, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, R. Fersch, A. Filippi, T. Forest, G. Gavalian, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, T.B. Hayward, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, M. Khachatryan, A. Khanal, M. Khandaker, A. Kim, C.W. Kim, F.J. Klein, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, V. Lucherini, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, B. McKinnon, S. Mey-Tal Beck, T. Mineeva, M. Mirazita, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, K. Neupane, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, R.A. Schumacher, E.P. Segarra, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, T. Wang, D. Watts, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and X. Zheng

Subjects
Physics, QC1-999
Abstract

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e,e′p) and 12C(e,e′pN) reactions (where N is either n or p), at high-Q2 and xB>1.1. The data span a missing-momentum range of 300–1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon (NN) interaction models. This agreement suggests that the measured high missing-momentum protons up to 1000 MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured 12C(e,e′pN) / 12C(e,e′p) and 12C(e,e′pp) / 12C(e,e′pn) cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor NN interaction at ∼400 MeV/c to an isospin-independent scalar interaction at high-momentum around ∼800 MeV/c as predicted by theoretical calculation.

Published
2021
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3. Double polarisation observable G for single pion photoproduction from the proton

Author

N. Zachariou, D.P. Watts, J. McAndrew, L. Zana, M. Bashkanov, I.I. Strakovsky, R. Workman, A.V. Sarantsev, V. Nikonov, K.P. Adhikari, S. Adhikari, M.J. Amaryan, G. Angelini, W.R. Armstrong, H. Atac, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, D.S. Carman, J.C. Carvajal, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, G. Gavalian, G.P. Gilfoyle, F.X. Girod, D.I. Glazier, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, M. Hattawy, D. Heddle, K. Hicks, A. Hobart, M. Holtrop, Q. Huang, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, A. Khanal, M. Khandaker, A. Kim, F.J. Klein, A. Kripko, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, Z.E. Meziani, T. Mineeva, V. Mokeev, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, K. Neupane, A. Ni, S. Niccolai, G. Niculescu, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, O. Pogorelko, Y. Prok, D. Protopopescu, M. Ripani, B.G. Ritchie, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, A. Schmidt, R.A. Schumacher, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, S. Strauch, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, X. Wei, B. Yale, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report measurements of π+ and π0 meson photoproduction from longitudinally spin-polarised protons by an energy tagged (0.73-2.3 GeV) and linearly polarised photon beam. A close to complete solid angle coverage for the reaction products was provided by the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The double-polarisation observable G is extracted from Maximum Likelihood fits to the data, enabling the first accurate determination for the reaction γ→p→→π+n, while also significantly extending the kinematic coverage for γ→p→→π0p. This large data set provides an important constraint on the properties and spectrum of excited nucleon states decaying to Nπ in the mass range from 1.4 to 2.2 GeV, as well as for background (non-resonant) photoproduction processes. The considerable improvement achieved in the description of the observable G within the SAID and Bonn-Gatchina approaches after implementation of our data, illustrates that the partial-wave analyses now significantly extend the knowledge on Nπ photoproduction amplitudes at W>1.8 GeV. A partial-wave analysis using the new high-precision data set has a large impact on the extracted properties of high-spin nucleon excited states.

Published
2021
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4. First results on nucleon resonance photocouplings from the γp → π+π−p reaction

Author

E. Golovatch, V.D. Burkert, D.S. Carman, R.W. Gothe, K. Hicks, B.S. Ishkhanov, V.I. Mokeev, E. Pasyuk, S. Adhikari, Z. Akbar, M.J. Amaryan, H. Avakian, J. Ball, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, F. Cao, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, D. Heddle, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, S. Johnston, K. Joo, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, B. McKinnon, C.A. Meyer, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, D. Riser, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, N. Tyler, M. Ungaro, H. Voskanyan, E. Voutier, R. Wang, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+π−p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV

Published
2019
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5. Evidence for the N′(1720)3/2+ nucleon resonance from combined studies of CLAS π+π−p photo- and electroproduction data

Author

V.I. Mokeev, V.D. Burkert, D.S. Carman, L. Elouadrhiri, E. Golovatch, R.W. Gothe, K. Hicks, B.S. Ishkhanov, E.L. Isupov, K. Joo, N. Markov, E. Pasyuk, and A. Trivedi

Subjects
Two pion production, Resonance couplings, Missing resonances, Physics, QC1-999
Abstract

The analysis of the nine 1-fold differential cross sections for the γr,vp→π+π−p photo- and electroproduction reactions obtained with the CLAS detector at Jefferson Laboratory was carried out with the goal to establish the contributing resonances in the mass range from 1.6 GeV to 1.8 GeV. In order to describe the photo- and electroproduction data with Q2-independent resonance masses and hadronic decay widths in the Q2 range below 1.5 GeV2, it was found that an N′(1720)3/2+ state is required in addition to the already well-established nucleon resonances. This work demonstrates that the combined studies of π+π−p photo- and electroproduction data are vital for the observation of this resonance. The contributions from the N′(1720)3/2+ state and the already established N(1720)3/2+ state with a mass of 1.745 GeV are well separated by their different hadronic decays to the πΔ and ρp final states and the different Q2-evolution of their photo-/electroexcitation amplitudes. The N′(1720)3/2+ state is the first recently established baryon resonance for which the results on the Q2-evolution of the photo-/electrocouplings have become available. These results are important for the exploration of the nature of the “missing” baryon resonances.

Published
2020
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6. Semi-inclusive π0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS

Author

S. Jawalkar, S. Koirala, H. Avakian, P. Bosted, K.A. Griffioen, C. Keith, S.E. Kuhn, K.P. Adhikari, S. Adhikari, D. Adikaram, Z. Akbar, M.J. Amaryan, S. Anefalos Pereira, J. Ball, N.A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, J. Brock, W.K. Brooks, S. Bültmann, V.D. Burkert, Frank Thanh Cao, C. Carlin, D.S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P.L. Cole, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, C. Djalali, G. Ddoge, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, R. Fersch, A. Filippi, J.A. Fleming, T.A. Forest, A. Fradi, M. Garçon, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, C. Gleason, W. Gohn, E. Golovatch, R.W. Gothe, M. Guidal, N. Guler, L. Guo, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, G. Hollis, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, N. Markov, M. Mayer, M.E. McCracken, B. McKinnon, C.A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A.I. Ostrovidov, R. Paremuzyan, K. Park, E. Pasyuk, E. Phelps, W. Phelps, J. Pierce, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, D. Riser, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, E. Seder, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I. Stankovic, S. Strauch, M. Taiuti, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, X. Wei, L.B. Weinstein, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
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 14NH3 target, and extracted double and single target spin asymmetries for ep→e′π0X in multidimensional bins in four-momentum transfer (1.0

Published
2018
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7. Hard exclusive pion electroproduction at backward angles with CLAS

Author

K. Park, M. Guidal, R.W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J.-M. Laget, K.P. Adhikari, S. Adhikari, Z. Akbar, H. Avakian, J. Ball, I. Balossino, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, W.J. Briscoe, W.K. Brooks, V.D. Burkert, F.T. Cao, D.S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, M. Garçon, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, E. Golovatch, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, C.E. Hyde, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, S. Johnston, K. Joo, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, W. Kim, F.J. Klein, V. Kubarovsky, S.E. Kuhn, L. Lanza, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, M. Mirazita, V. Mokeev, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, M. Paolone, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J. Poudel, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, A. Rizzo, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, Y. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, M. Ungaro, H. Voskanyan, E. Voutier, X. Wei, N. Zachariou, and J. Zhang

Subjects
Physics, QC1-999
Abstract

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep→e′nπ+, above the resonance region at backward pion center-of-mass angles. The φπ⁎-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of three-quark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon. Keywords: TDA, Exclusive single pion, Eletroproduction, CLAS

Published
2018
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8. Photon beam asymmetry Σ for η and η′ photoproduction from the proton

Author

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. Adhikari, Z. Akbar, M.J. Amaryan, S. Anefalos Pereira, H. Avakian, J. Ball, I. Balossino, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, 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, and J. Zhang

Subjects
Physics, QC1-999
Abstract

Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η′ 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 γp→ηp reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γp→η′p reaction. For γp→ηp, 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 γp→η′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. Keywords: Meson photoproduction, Eta photoproduction, Eta-prime photoproduction, Polarization observable, Photon beam asymmetry

Published
2017
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9. First measurement of the helicity asymmetry E in η photoproduction on the proton

Author

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. Rönchen, M. Döring, 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. Credé, 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, G. Fedotov, S. Fegan, A. Filippi, J.A. Fleming, A. Fradi, 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. Sabatié, C. Salgado, D. Schott, R.A. Schumacher, E. Seder, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, 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, and I. Zonta

Subjects
Physics, QC1-999
Abstract

Results are presented for the first measurement of the double-polarization helicity asymmetry E for the η photoproduction reaction γp→ηp. 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 Jülich–Bonn 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 from that model. Further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances. Keywords: Eta photoproduction, Polarization observable, Helicity asymmetry

Published
2016
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10. First measurement of the polarization observable E in the p→(γ→,π+)n reaction up to 2.25 GeV

Author

S. Strauch, W.J. Briscoe, M. Döring, E. Klempt, V.A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K.P. Adhikari, D. Adikaram, M.D. Anderson, S. Anefalos Pereira, A.V. Anisovich, R.A. Badui, J. Ball, V. Batourine, M. Battaglieri, I. Bedlinskiy, N. Benmouna, A.S. Biselli, J. Brock, W.K. Brooks, V.D. Burkert, T. Cao, C. Carlin, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P.L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, N. Dashyan, A. D'Angelo, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J.A. Fleming, T.A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, K.L. Giovanetti, F.X. Girod, D.I. Glazier, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, D. Ho, 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, C.D. Keith, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, N. Markov, B. McKinnon, D.G. Meekins, C.A. Meyer, V. Mokeev, R.A. Montgomery, C.I. Moody, H. Moutarde, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, G. O'Rielly, M. Osipenko, A.I. Ostrovidov, K. Park, P. Peng, W. Phelps, J.J. Phillips, S. Pisano, O. Pogorelko, S. Pozdniakov, J.W. Price, S. Procureur, Y. Prok, D. Protopopescu, A.J.R. Puckett, B.A. Raue, M. Ripani, B.G. Ritchie, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, D. Schott, R.A. Schumacher, E. Seder, M.L. Seely, I. Senderovich, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, P. Stoler, S. Stepanyan, V. Sytnik, M. Taiuti, Ye Tian, A. Trivedi, R. Tucker, 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, and I. Zonta

Subjects
Baryon spectroscopy, Pion photoproduction, Polarization observables, FROST experiment, Physics, QC1-999
Abstract

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction γ→p→→π+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, Jülich–Bonn, and SAID groups.

Published
2015
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11. The Present and Future of QCD: QCD Town Meeting White Paper -- An INput to the 2023 NSAC Long Range Plan

Author

P Achenbach, D Adhikari, A Afanasev, F Afzal, C Aidala, A Al-bataineh, D Almaaloi, M Amaryan, D Androic, W Armstrong, M Arriatia, J Arrington, A Asaturyan, E Aschenauer, H Atac, H Avakian, T Averett, C Ayerbe Gayoso, X Bai, K Barish, N Barnea, G Basar, M Battaglieri, A Baty, I Bautista, A Bazilevsky, C Beattie, S Behera, V Bellini, R Bellwied, J Benesch, F Benmokhtar, C Bernardes, J Bernauer, H Bhatt, S Bhatta, M Boer, T Boettcher, S Bogacz, H Bossi, J Brandenburg, E Brash, R Briceno, W Briscoe, S Brodsky, D Brown, V Burkert, H Caines, I Cali, A Camsonne, D Carman, J Caylor, S Cerci, M Chamizo Llatas, J Chen, Y Chen, Y Chien, P Chou, X Chu, E Chudakov, E Cline, I Cloet, P Cole, M Conners, M Constantinou, W Cosyn, S Covrig Dusa, R Cruz-Torres, U D'Alesio, C da Silva, Z Davoudi, C Dean, D Dean, M Demarteau, A Deshpande, W Detmold, A Deur, B Devkota, S Dhital, M Diefenthaler, S Dobbs, M Doring, X Dong, R Dotel, K Dow, E Downie, J Drachenberg, A Dumitru, J Dunlop, R Dupre, J Durham, D Dutta, R Edwards, R Ehlers, L El Fassi, M Elaasar, L Elouadrhiri, M Engelhardt, R Ent, S Esumi, O Evdokimov, O Eyser, C Fanelli, R Fatemi, I Fernando, F Flor, N Fomin, A Frawley, T Federico, R Fries, C Gal, B Gamage, L Gamberg, H Gao, D Gaskell, F Geurts, Y Ghandilyan, R Gilman, C Gleason, K Gnanvo, R Gothe, S Greene, H Griesshammer, S Grossberndt, B Grube, D Hackett, T Hague, H Hakobyan, J Hansen, Y Hatta, M Hattawy, L Havener, O Hen, W Henry, D Higinbotham, T Hobbs, A Hodges, T Holmstrom, B Hong, T Horn, C Howell, H Huang, M Huang, S Huang, G Huber, C Hyde, E Isupov, P Jacobs, J Jalilian-Marian, A Jentsch, H Jheng, C Ji, X Ji, J Jia, D Jones, M Jones, N Kalantarians, G Kalicy, Z Kang, J Karthein, D Keller, C Keppel, V Khachartryan, D Kharzeev, M Kim, Y Kim, P King, E Kinney, S Klein, H Ko, V Koch, M Kohl, Y Kovchegov, G Krintiras, V Kubarovsky, S Kuhn, K Kumar, T Kutz, J Lajoie, J Lauret, I Lavrukhin, D Lawrence, J Lee, K Lee, S Lee, Y Lee, S Li, W Li, X Li, J Liao, H Lin, M Lisa, K Liu, M Liu, T Liu, S Liuti, N Liyanage, W Llope, C Loizides, R Longo, W Lorenzon, X Luo, R Ma, B McKinnon, D Meekins, Y Mehtar-Tani, W Melnitchouk, A Metz, C Meyer, Z Meziani, R Michaels, R Milner, H Mkrtchyan, P Mohanmurthy, B Mohanty, V Mokeev, I Mooney, C Morningstar, D Morrison, B Muller, S Mukherjee, J Mulligan, C Munoz Camacho, J Murillo Quijada, M Murray, S Nadeeshani, P Nadel-Turonski, J Nam, C Nattrass, G Nijs, J Norohna, J Noronha-Hostler, N Novitzky, M Nycz, F Olness, J Osborn, R Pak, B Pandey, M Paolone, Z Papandreou, J Paquet, S Park, K Paschke, B Pasquini, E Pasyuk, T Patel, A Patton, C Paudel, C Peng, J Peng, H Pereira Da Costa, D Perepelitsa, M Peters, P Petreczky, R Pisarski, D Pitonyak, M Ploskon, M Posik, J Poudel, R Pradhan, A Prokudin, C Pruneau, J Putschke, J Pybus, J Qiu, K Rajagopal, C Ratti, K Read, R Reed, D Richards, C Riedl, F Ringer, T Rinn, J Rittenhouse West, J Roche, A Rodas, G Roland, F Romero-Lopez, P Rossi, T Rostomyan, L Ruan, O Ruimi, N Saha, N Sahoo, T Sakaguchi, F Salazar, C Salgado, G Salme, S Salur, S Santiesteban, M Sargsian, M Sarsour, N Sato, T Satogata, S Sawada, T Schafer, B Scheihing-Hitschfeld, B Schenke, S Schindler, A Schmidt, R Seidl, M Sabestari, P Shanahan, C Shen, T Sheng, M Shepherd, A M Sickles, M Sievert, K Smith, Y Song, A Sorensen, P Souder, N Spareveris, S Srednyak, A Stahl Leiton, A Stasto, P Steinberg, S Stepanyan, M Stephanov, J Stevens, D Stewart, I Stewart, M Stojanovic, I Strakovsky, S Strauch, M Strickland, D Sunar Cerci, M Suresh, B Surrow, S Syritsyn, A Szczepaniak, A Tadepalli, A H Tang, J Tapia Takaki, T Tarnowsky, A Tawfik, M Taylor, C Tennant, A Thiel, D Thomas, Y Tian, A Timmins, P Tribedy, Z Tu, S Tuo, T Ullrich, E Umaka, N Ghimire, J Vary, J Velkovska, R Venugopalan, A Vijayakumar, I Vitev, W Vogelsang, R Vogt, A Vossen, E Voutier, V Vovchenko, A Walker-Loud, F Wang, J Wang, X Wang, L Weinstein, T Wenaus, S Weyhmiller, S Wissink, B Wojtsekhowski, C Wong, M Wood, Y Wunderlich, B Wyslouch, B Xiao, W Xie, W Xiong, N Xu, Q Xu, Z Xu, D Yaari, X Yao, Z Ye, C Yero, F Yuan, W Zajc, C Zhang, J Zhang, F Zhao, Y Zhao, Z Zhao, X Zheng, and J Zhou

Published
2023

12. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author

S.J. Paul, A. Peck, M. Arratia, Y. Gotra, V. Ziegler, R. De Vita, F. Bossù, M. Defurne, H. Atac, C. Ayerbe Gayoso, L. Baashen, N.A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A.S. Biselli, M. Bondi, S. Boiarinov, K.-Th. Brinkmann, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, R. Capobianco, D.S. Carman, J.C. Carvajal, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, P.L. Cole, G. Costantini, A. D’Angelo, N. Dashyan, A. Deur, S. Diehl, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, A. Filippi, K. Gates, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, A.A. Golubenko, G. Gosta, R.W. Gothe, K. Griffioen, M. Guidal, H. Hakobyan, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, H.S. Jo, R. Johnston, K. Joo, D. Keller, M. Khachatryan, A. Khanal, A. Kim, W. Kim, V. Klimenko, A. Kripko, L. Lanza, M. Leali, P. Lenisa, X. Li, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, C. McLauchlin, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, D. Nguyen, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, P. Pandey, M. Paolone, R. Paremuzyan, N. Pilleux, O. Pogorelko, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, T. Reed, M. Ripani, J. Ritman, F. Sabatié, S. Schadmand, A. Schmidt, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, M. Spreafico, I.I. Strakovsky, S. Strauch, J.A. Tan, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Wishart, M.H. Wood, N. Zachariou, 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), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, data analysis method, Physics - Instrumentation and Detectors, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ddc:530, tracking detector, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), numerical calculations, Nuclear Experiment, Instrumentation, Alignment, track data analysis, Settore FIS/04, Detector, Instrumentation and Detectors (physics.ins-det), detector: alignment, Kalman filter, cosmic radiation, semiconductor detector: microstrip, performance
Abstract

International audience; Several factors can contribute to the difficulty of aligning the sensors of tracking detectors, including a large number of modules, multiple types of detector technologies, and non-linear strip patterns on the sensors. The latter two of these three factors apply to the CLAS12 CVT, which is a hybrid detector consisting of planar silicon sensors with non-parallel strips, and cylindrical micromegas sensors with longitudinal and arc-shaped strips located within a 5 T superconducting solenoid. To align this detector, we used the Kalman Alignment Algorithm, which accounts for correlations between the alignment parameters without requiring the time-consuming inversion of large matrices. This is the first time that this algorithm has been adapted for use with hybrid technologies, non-parallel strips, and curved sensors. We present the results for the first alignment of the CLAS12 CVT using straight tracks from cosmic rays and from a target with the magnetic field turned off. After running this procedure, we achieved alignment at the level of l. 967 10μm, and the widths of the residual spectra were greatly reduced. These results attest to the flexibility of this algorithm and its applicability to future use in the CLAS12 CVT and other hybrid or curved trackers, such as those proposed for the future Electron-Ion Collider.

Published
2023

13. Measurement of deeply virtual Compton scattering off He4 with the CEBAF Large Acceptance Spectrometer at Jefferson Lab

Author

T. A. Forest, D. P. Watts, H. Egiyan, F. Sabatié, D. Bulumulla, A. Filippi, Aditya R. Khanal, M. Khandaker, G. Rosner, Andrea Bianconi, D. Payette, Jo H. S., Y. Ghandilyan, H. Voskanyan, W. Kim, R. A. Schumacher, P. Lenisa, S. Bültmann, W. J. Briscoe, E. Pasyuk, Maxime Defurne, N. Markov, B. Torayev, R. Dupre, D. G. Ireland, Carlos A. Salgado, V. Crede, B. A. Clary, M. Contalbrigo, K. Livingston, M. Battaglieri, M. J. Amaryan, B. Yale, G. Costantini, S. Stepanyan, V. P. Kubarovsky, A. Kim, R. De Vita, J. Rowley, Whitney Armstrong, Simonetta Liuti, Krishna Neupane, J. Poudel, O. Pogorelko, K. Wei, S. Fegan, P. Eugenio, Dustin Keller, R. Paremuzyan, G. Khachatryan, Volker D. Burkert, M. L. Kabir, H. Atac, T. B. Hayward, Paolo Rossi, A. S. Biselli, R. Wishart, A. Celentano, R. W. Gothe, M. Guidal, K. Hafidi, V. Mokeev, Larry Weinstein, Gerard Gilfoyle, L. Venturelli, Michael Paolone, E. L. Isupov, D. Sokhan, M. Ehrhart, M. Caudron, M. Osipenko, S. Boiarinov, I. J. D. MacGregor, F. Bossu, A. Vossen, G. Ciullo, Fatiha Benmokhtar, Y. Prok, D. S. Carman, M. Holtrop, O. Soto, N. A. Baltzell, Nikos Sparveris, X. Wei, H. Hakobyan, M. H. Wood, E. Voutier, J. Ritman, S. Diehl, N. Dashyan, A. El Alaoui, B. McKinnon, Luciano Pappalardo, M. Bondì, K. A. Griffioen, Yordanka Ilieva, C. Ayerbe Gayoso, Nicholas Zachariou, J. C. Carvajal, Y. Perrin, V. Chesnokov, L. Barion, U. Shrestha, M. Mirazita, L. Lanza, K. Hicks, W. Phelps, V. Mascagna, D. Marchand, S. Niccolai, Alessandro Rizzo, Alexander Schmidt, I. Bedlinskiy, M. Ripani, P. Chatagnon, M. Ungaro, K. Joo, V. Sergeyeva, J. Zhang, F. X. Girod, N. Tyler, C. Djalali, T. Chetry, S. Strauch, L. Elouadrhiri, S. Joosten, I. I. Strakovsky, A. Deur, D. G. Jenkins, A. Hobart, M. Leali, T. R. O'Connell, N. Pivnyuk, A. D'Angelo, L. El Fassi, S. E. Kuhn, M. Hattawy, P. L. Cole, Martin K. Mayer, A. Kripko, and Y. G. Sharabian

Subjects
Nuclear physics, Physics, Spectrometer, 010308 nuclear & particles physics, 0103 physical sciences, Compton scattering, Perturbative QCD, 010306 general physics, 01 natural sciences
Published
2021

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

Author

J. Rowley, A. I. Ostrovidov, Volker D. Burkert, A. S. Biselli, W. Phelps, K. A. Griffioen, V. Mascagna, N. Markov, M. E. McCracken, A. Hobart, Carlos A. Salgado, A. Filippi, A. Pilloni, Frank Klein, Dustin Keller, P. Eugenio, L. Marsicano, Sylvester Joosten, Maxime Defurne, M. Khandaker, M. Khachatryan, M. Osipenko, Pawel Nadel-Turonski, Michael Paolone, Alexander Schmidt, D. I. Glazier, D. Bulumulla, E. Munevar, B. S. Ishkhanov, Aditya R. Khanal, Nikolaos Sparveris, M. Ungaro, K. Hafidi, F. Bossu, M. Guidal, G. Niculescu, L. Lanza, D. G. Jenkins, I. J. D. MacGregor, R. De Vita, M. Leali, Laura Clark, M. J. Amaryan, Andrea Bianconi, C. W. Kim, W. Kim, W. Gohn, F. X. Girod, N. Tyler, C. Djalali, J. A. Tan, P. Chatagnon, G. V. Fedotov, H. Voskanyan, A. D'Angelo, T. Chetry, I. Bedlinskiy, L. Elouadrhiri, M. Holtrop, F. Hauenstein, W. J. Briscoe, E. Pasyuk, S. Strauch, K. Joo, H. Atac, D. P. Watts, H. Egiyan, G. Angelini, L. El Fassi, I. I. Strakovsky, R. Dupre, M. Battaglieri, F. Sabatié, Luciano Pappalardo, D. Heddle, A. Deur, M. Ripani, G. Gavalian, V. Mokeev, D. Marchand, V. Lucherini, V. P. Kubarovsky, Michael Dugger, Fatiha Benmokhtar, Krishna Neupane, R. G. Fersch, O. Pogorelko, O. Soto, S. Niccolai, Vincent Mathieu, P. L. Cole, Z. W. Zhao, Alessandro Rizzo, E. Golovatch, P. Lenisa, K. Hicks, M. Ehrhart, S. Adhikari, T. B. Hayward, J. Zhang, M. Hattawy, J. W. Price, N. Dashyan, Yordanka Ilieva, L. Barion, G. Rosner, William Brooks, G. Ciullo, Y. Prok, L. Venturelli, D. S. Carman, R. A. Schumacher, A. El Alaoui, X. Wei, Nicholas Zachariou, J. C. Carvajal, S. Stepanyan, E. Voutier, A. Movsisyan, Adam P. Szczepaniak, D. Sokan, Z. E. Meziani, K. Livingston, K. P. Adhikari, H. Hakobyan, H. S. Jo, A. Kim, J. Ritman, S. Diehl, D. G. Ireland, V. Crede, O. Cortes, E. L. Isupov, R. Paremuzyan, S. Boiarinov, R. Cruz-Torres, Nicholas M. Harrison, U. Shrestha, M. Contalbrigo, C. Munoz Camacho, M. H. Wood, B. McKinnon, A. Celentano, R. W. Gothe, M. Mirazita, and N. Gevorgyan

Subjects
Physics, Meson, 010308 nuclear & particles physics, Partial wave analysis, Hadron, Sigma, Photon energy, 01 natural sciences, Nuclear physics, Amplitude, 0103 physical sciences, Invariant mass, Nuclear Experiment, 010306 general physics, Phenomenology (particle physics)
Abstract

We present the first measurement of the exclusive reaction $\gamma p \rightarrow a_2(1320)^0 \, p$ in the photon energy range $3.5$-$5.5$ GeV and four-momentum transfer squared $0.2

Published
2020

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

Author

Frank Klein, Dustin Keller, K. Hafidi, E. Golovatch, Y. G. Sharabian, K. Hicks, M. Ripani, C. Bookwalter, K. A. Griffioen, L. Lanza, H. Egiyan, V. Crede, I. J. D. MacGregor, M. Contalbrigo, S. Adhikari, M. Hattawy, C. Munoz Camacho, M. H. Wood, B. McKinnon, I. Bedlinskiy, D. Protopopescu, Michael Dugger, M. Osipenko, L. Elouadrhiri, M. Khachatryan, M. S. Saini, G. Ciullo, P. Eugenio, M. Taiuti, A. El Alaoui, Carlos A. Salgado, F. Cao, W. Kim, I. I. Strakovsky, Maxime Defurne, A. Deur, J. T. Goetz, Y. Prok, D. S. Carman, M. Mirazita, Nikos Sparveris, B. S. Ishkhanov, Nicholas Zachariou, M. L. Kabir, Diane Schott, Michael Paolone, C. A. Meyer, A. I. Ostrovidov, K. Park, X. Wei, N. Gevorgyan, D. I. Glazier, P. Chatagnon, G. V. Fedotov, D. G. Ireland, R. De Vita, M. Guidal, E. Voutier, A. Movsisyan, J. Zhang, F. Sabatié, G. Niculescu, S. Chandavar, V. P. Kubarovsky, Volker D. Burkert, A. S. Biselli, K. Livingston, J. W. Price, A. Celentano, R. W. Gothe, S. Anefalos Pereira, R. Paremuzyan, D. Riser, V. Mokeev, D. P. Weygand, A. Filippi, M. C. Kunkel, Brian Raue, O. Pogorelko, Nicholas M. Harrison, Rong Wang, M. Holtrop, S. Niccolai, R. Dupre, M. Battaglieri, M. Khandaker, Alessandro Rizzo, D. Sokhan, D. I. Sober, L. Guo, M. Ehrhart, M. Ungaro, Pawel Nadel-Turonski, H. Voskanyan, W. J. Briscoe, E. Pasyuk, Iu. Skorodumina, D. Heddle, Taya Chetry, William Brooks, P. L. Cole, Z. W. Zhao, R. A. Schumacher, A. D'Angelo, F. X. Girod, L. El Fassi, S. Strauch, E. L. Isupov, S. Boiarinov, H. Hakobyan, H. S. Jo, S. Diehl, Sylvester Joosten, C. Djalali, J. A. Tan, G. Khachatryan, N. Dashyan, A. Kim, G. Rosner, and Y. Ghandilyan

Subjects
Quark, Physics, Particle physics, 010308 nuclear & particles physics, Nuclear Theory, Quark model, Lattice field theory, 01 natural sciences, Xi baryon, Baryon, Lattice (order), Excited state, 0103 physical sciences, High Energy Physics::Experiment, Gauge theory, Nuclear Experiment, 010306 general physics
Abstract

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

Published
2018

16. Search for a dark photon in electroproduced e+e− pairs with the Heavy Photon Search experiment at JLab

Author

S. Paul, O. Moreno, M. Osipenko, M. Carpinelli, M. Garçon, B. Reese, H. Egiyan, Volker D. Burkert, P. H. Adrian, K. Livingston, L. Elouadrhiri, R. Essig, L. Colaneri, Bogdan Wojtsekhowski, A. Filippi, R. Dupre, M. Battaglieri, B. Raydo, N. Randazzo, William T. Cooper, M. Khandaker, S. Boyarinov, K. McCarty, A. Deur, M. Guidal, A. P. Freyberger, Norman A. Graf, C. Munoz Camacho, S. Uemura, M. Holtrop, S. Bueltmann, H. Szumila-Vance, K.C. Moffeit, Valeria Sipala, C. Field, M. T. Graham, R. Paremuzyan, M. Solt, F. X. Girod, A. D'Angelo, G. Charles, D. Calvo, R. De Vita, C. Cuevas, M. Bondì, Emanuele Leonora, G. Kalicy, D. Sokhan, Ryan Herbst, B. McKinnon, M. De Napoli, Philip Schuster, Alexander Grillo, M. Oriunno, Larry Weinstein, N. Dashyan, A. Celentano, Vitaliy Fadeyev, Y. G. Sharabian, B. Yale, S. Stepanyan, A. Simonyan, N. Gevorgyan, Natalia Toro, J. A. Jaros, N. A. Baltzell, V. P. Kubarovsky, G. Simi, Jeremy McCormick, S. Niccolai, H. Voskanyan, Alessandro Rizzo, A.C. Odian, T. Maruyama, M. Ungaro, T. K. Nelson, and K. A. Griffioen

Subjects
Coupling, Physics, Photon, Luminosity (scattering theory), 010308 nuclear & particles physics, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Dark photon, Standard Model, Nuclear physics, 0103 physical sciences, Cathode ray, Invariant mass, 010306 general physics
Abstract

The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for a prompt, electroproduced dark photon with a mass between 19 and 81 MeV/c2. A search for a resonance in the e+e- invariant mass distribution, using 1.7 days (1170 nb-1) of data, showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square of the coupling of the dark photon to the standard model photon are set at the level of 6×10-6. Future runs with higher luminosity will explore new territory.

Published
2018

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

Author

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

Subjects
Quark, Quantum chromodynamics, Physics, Meson, 010308 nuclear & particles physics, Perturbative QCD, Parton, Mandelstam variables, Photon energy, 01 natural sciences, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Sum rule in quantum mechanics, 010306 general physics
Abstract

Exclusive photoproduction cross sections have been measured for the process γ p → p π 0 [ e + e − ( γ ) ] with the Dalitz decay final state using tagged photon energies in the range of E γ = 1.275 – 5.425 GeV. The complete angular distribution of the final state π 0 , for the entire photon energy range up to large values of t and u , has been measured for the first time. The data obtained show that the cross section d σ / d t , at mid to large angles, decreases with energy as s − 6.89 ± 0.26 . This is in agreement with the perturbative QCD quark counting rule prediction of s − 7 . Paradoxically, the size of angular distribution of measured cross sections is greatly underestimated by the QCD-based generalized parton distribution mechanism at highest available invariant energy s = 11 GeV 2 . At the same time, the Regge-exchange-based models for π 0 photoproduction are more consistent with experimental data.

Published
2018

18. Measurement of the beam asymmetry Σ and the target asymmetry T in the photoproduction of ω mesons off the proton using CLAS at Jefferson Laboratory

Author

William Brooks, George Davey Smith, R. A. Schumacher, A. El Alaoui, S. Stepanyan, J. Pierce, H. Y. Lu, P. Eugenio, G. Gavalian, I. Denisenko, N. Dashyan, Taya Chetry, M. Taiuti, A. Filippi, A. Fradi, D. P. Watts, K. A. Griffioen, Friedrich Klein, V. Crede, M. Khandaker, D. G. Meekins, Brian Raue, A. D'Angelo, A. V. Sarantsev, Yordanka Ilieva, Nicholas Zachariou, E. Pasyuk, V. Mokeev, V. Batourine, R. Paremuzyan, R. De Vita, N. Markov, L. Lanza, G. Rosner, E. Golovatch, K. Hicks, W. Kim, Sergey Kuleshov, M. Ripani, R. A. Montgomery, F. Sabatié, S. Niccolai, Carlos A. Salgado, C. D. Keith, Pawel Nadel-Turonski, D. G. Jenkins, Eberhard Klempt, B. A. Clary, J. Brock, Alessandro Rizzo, R. Dupre, M. Battaglieri, J. Zhang, C. Djalali, J. A. Tan, L. El Fassi, J. W. Price, S. Anefalos Pereira, K. Livingston, C. Hanretty, C. Carlin, M. Guidal, L. Guo, M. Ungaro, Gerard Gilfoyle, A. I. Ostrovidov, A. V. Anisovich, K. Park, G. Charles, G. Niculescu, V. A. Nikonov, G. Ciullo, J. P. Ball, B. Torayev, Y. Prok, F. X. Girod, M. E. McCracken, D. S. Carman, D. G. Ireland, M. Holtrop, K. Joo, I. Bedlinskiy, V. P. Kubarovsky, D. Riser, M. Osipenko, Andreas Klein, Nikos Sparveris, X. Wei, T. Mineeva, D. Sokhan, O. Pogorelko, S. Procureur, W. Gohn, A. Kim, Z. E. Meziani, W. Phelps, Volker D. Burkert, M. Bashkanov, A. S. Biselli, B. S. Ishkhanov, L. Elouadrhiri, K. L. Giovanetti, I. Balossino, S. Strauch, Michael Dugger, D. I. Sober, E. Voutier, I. I. Strakovsky, A. Movsisyan, B. McKinnon, Dustin Keller, S. Park, A. Deur, K. Hafidi, Iu. Skorodumina, Sylvester Joosten, S. Fegan, G. Khachatryan, P. L. Cole, Z. W. Zhao, E. Phelps, N. Gevorgyan, D. Protopopescu, W. J. Briscoe, C. Munoz Camacho, M. H. Wood, A. Celentano, R. W. Gothe, M. Contalbrigo, Z. Akbar, N. K. Walford, I. J. D. MacGregor, S. Adhikari, M. Hattawy, Martin K. Mayer, Y. G. Sharabian, C. Gleason, Barry Ritchie, P. Roy, C. A. Meyer, G. V. Fedotov, E. L. Isupov, S. Boiarinov, K. P. Adhikari, H. Hakobyan, and P. Lenisa

Subjects
Physics, Particle physics, Proton, Meson, 010308 nuclear & particles physics, Partial wave analysis, media_common.quotation_subject, Nuclear Theory, Bremsstrahlung, Observable, 7. Clean energy, 01 natural sciences, Resonance (particle physics), Asymmetry, Baryon, Nuclear physics, 13. Climate action, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, media_common
Abstract

The photoproduction of ω mesons off the proton has been studied in the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω→π+π-π0, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry Σ are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional ω photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from s-channel resonance production were found in addition to t-channel exchange processes.

Published
2018

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

Author

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

Subjects
Quantum chromodynamics, Physics, Particle physics, Proton, 010308 nuclear & particles physics, Virtual particle, Parton, Deep inelastic scattering, 01 natural sciences, Nuclear physics, 0103 physical sciences, Proton spin crisis, High Energy Physics::Experiment, Operator product expansion, Nuclear Experiment, 010306 general physics, Spin-½
Abstract

We present the results of our final analysis of the full data set of g1p(Q2), the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000–2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets (NH315 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries A1p and A2p and spin structure functions g1p and g2p over a wide kinematic range (0.05 GeV2

Published
2017

20. Beam-Target Helicity Asymmetry for γ→n→→π−p in the N* Resonance Region

Author

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

Subjects
Physics, Photon, 010308 nuclear & particles physics, General Physics and Astronomy, 7. Clean energy, 01 natural sciences, Helicity, Nuclear physics, Deuterium, Solid hydrogen, Isospin, 0103 physical sciences, Neutron, Invariant mass, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

We report the first beam-target double-polarization asymmetries in the γ þ nðpÞ → π− þ pðpÞ reaction spanning the nucleon resonance region from invariant mass W ¼ 1500 to 2300 MeV. Circularly polarized photons and longitudinally polarized deuterons in solid hydrogen deuteride (HD) have been used with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the E polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses and have led to significant revisions for several γnN* resonance photocouplings.

Published
2017

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

Author

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, A, Biselli, 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, P, Eugenio, 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, 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, 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, E, Voutier, D P, Watts, M H, Wood, N, Zachariou, J, Zhang, and Z W, Zhao

Abstract

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

Published
2017

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

Author

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

Subjects
Physics, Particle physics, 010308 nuclear & particles physics, Scattering, Resonance, Electron, 01 natural sciences, Nuclear physics, Pion, Amplitude, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Sign (mathematics), Spin-½
Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(0) electroproduction reaction. gamma(*) p -> p pi(0), expanding an analysis of the. gamma(*) p -> 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 Laboratory. The kinematic ranges covered are 1.1 < W < 3 GeV and 1 < Q(2) < 6 GeV2. Results were obtained for about 5700 bins in W, Q(2), cos(theta(*)), and phi(*). The beam-target asymmetries were found to generally be greater than zero, with relatively modest phi(*) dependence. The target asymmetries exhibit very strong phi(*) dependence, with a change in sign occurring between results at low W and high W, in contrast to pi(+) electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but significant differences are seen at higherW. When combined with cross-sectional measurements, as well as pi(+) observables, 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 2.4 GeV.

Published
2017

23. Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1GeV2 . I. ep→eπ+n

Author

Sylvester Joosten, P. Lenisa, B. McKinnon, I. Zonta, G. Ciullo, C. Djalali, J. P. Ball, Y. Prok, D. S. Carman, M. Mirazita, V. Crede, Nikos Sparveris, X. Wei, M. Osipenko, N. Gevorgyan, V. Batourine, H. Egiyan, R. A. Badui, M. Guidal, S. Niccolai, R. A. Montgomery, S. E. Kuhn, M. Hattawy, Brian Raue, K. A. Griffioen, J. A. Fleming, A. Filippi, M. Holtrop, G. Charles, Gerard Gilfoyle, D. Protopopescu, D. Sokhan, L. Colaneri, A. Fradi, Andrew Puckett, E. Voutier, W. Kim, S. Chandavar, I. Bedlinskiy, P. Eugenio, M. Taiuti, Laura Clark, M. Khandaker, R. W. Gothe, P. Rossi, E. Seder, P. L. Cole, Z. W. Zhao, I. Stankovic, K. Livingston, Yordanka Ilieva, Iu. Skorodumina, S. Pisano, K. Hicks, P. Peng, M. J. Amaryan, L. Lanza, C. Munoz Camacho, M. E. McCracken, S. Strauch, G. Murdoch, S. M. Hughes, P. Nadel-Turonski, M. Ripani, L. A. Net, S. Stepanyan, W. Phelps, C. Gleason, Larry Weinstein, S. Koirala, N. K. Walford, F. X. Girod, A. El Alaoui, I. J. D. MacGregor, Andrea Celentano, B. Torayev, A. I. Ostrovidov, K. Park, M. Contalbrigo, Nicholas Zachariou, C. A. Meyer, D. G. Ireland, H. Jiang, G. V. Fedotov, Volker D. Burkert, A. S. Biselli, H. Hakobyan, M. Battaglieri, H. S. Jo, W. Gohn, Victor Mokeev, L. Elouadrhiri, I. I. Strakovsky, E. Fanchini, A. Deur, J. Zhang, J. W. Price, M. Ungaro, E. Golovatch, R. Dupre, K. Joo, E. L. Isupov, Ye Tian, R. De Vita, S. Anefalos Pereira, E. De Sanctis, R. A. Schumacher, T. A. Forest, N. A. Baltzell, G. Khachatryan, W. J. Briscoe, G. Rosner, Y. Ghandilyan, A. Kim, E. Munevar, B. S. Ishkhanov, George Davey Smith, A. D'Angelo, Frank Klein, L. El Fassi, P. E. Bosted, H. Avakian, H. Voskanyan, S. Bültmann, E. Pasyuk, V. P. Kubarovsky, and O. Pogorelko

Subjects
Physics, Meson, 010308 nuclear & particles physics, Scattering, Form factor (quantum field theory), Resonance, Electron, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Spin-½
Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π 0 electroproduction reaction γ ∗ p → p π 0 , expanding an analysis of the γ ∗ p → n π + reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 < W < 3 GeV and 1 < Q 2 < 6 GeV 2 . Results were obtained for about 5700 bins in W , Q 2 , cos ( θ ∗ ) , and ϕ ∗ . The beam-target asymmetries were found to generally be greater than zero, with relatively modest ϕ ∗ dependence. The target asymmetries exhibit very strong ϕ ∗ dependence, with a change in sign occurring between results at low W and high W , in contrast to π + electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but significant differences are seen at higher W . When combined with cross-sectional measurements, as well as π + observables, 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 2.4 GeV.

Published
2017

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

Author

P. Roy, M. Guidal, V. Crede, S. Joosten, O. Pogorelko, Andrea Celentano, G. D. Smith, M. Holtrop, A. I. Ostrovidov, Paolo Rossi, Karl Slifer, D. G. Ireland, Andrew Puckett, R. A. Schumacher, Chaden Djalali, H. S. Jo, H. Jiang, Y. Ilieva, B. McKinnon, L. C. Smith, E. Munevar, I. Zonta, S. Strauch, Volker D. Burkert, A. S. Biselli, M. Osipenko, B. S. Ishkhanov, G. Ciullo, D. Keller, Nikolaos Sparveris, Taya Chetry, L. Colaneri, G. Khachatryan, Michael Paolone, P. Eugenio, M. Taiuti, S. Bültmann, Hyekoo Kang, L. El Fassi, P. Nadel-Turonski, H. Avakian, D. P. Watts, J. P. Ball, L. Clark, R. De Vita, A. Rizzo, M. Khandaker, D. G. Jenkins, X. Wei, M. Mirazita, A. Ni, S. Niccolai, L. Lanza, K. Hicks, R. W. Gothe, C. Salgado, M. J. Amaryan, N. Guler, A. Movsisyan, H. Egiyan, A. Filippi, G. Charles, Gerard Gilfoyle, I. I. Strakovsky, F. X. Girod, D. Adikaram, D. Sokhan, G. Murdoch, N. Markov, Seonho Choi, R. Paremuzyan, S. E. Kuhn, M. Battaglieri, K. Livingston, H. Voskanyan, E. Fanchini, K. L. Giovanetti, V. A. Drozdov, A. Deur, J. A. Fleming, J. P. Chen, E. Pasyuk, K. Kovacs, C. Gleason, G. E. Dodge, N. Gevorgyan, Larry Weinstein, C. Hanretty, W. Kim, W. J. Briscoe, F. Sabatié, E. De Sanctis, S. Pisano, S. K. Phillips, G. Niculescu, V. Batourine, S. Chandavar, N. A. Baltzell, R. Fersch, P. Bosted, E. Voutier, N. K. Walford, P. Lenisa, J. W. Price, P. Peng, L. Guo, M. Hattawy, I. Niculescu, G. Asryan, K. A. Griffioen, C. Munoz Camacho, I. Bedlinskiy, S. M. Hughes, E. N. Golovach, Victor Mokeev, P. L. Cole, N. Dashyan, K. Park, Iu. Skorodumina, R. Dupre, A. El Alaoui, I. Stankovic, R. A. Badui, I. J. D. MacGregor, M. Contalbrigo, Friedrich Klein, Brian Raue, Nicholas Zachariou, E. L. Isupov, G. V. Fedotov, N. Harrison, M. Ripani, L. A. Net, A. Kim, G. Rosner, N. Compton, Ye Tian, V. P. Kubarovsky, Annalisa D'Angelo, K. P. Adhikari, Z. Akbar, L. Elouadrhiri, S. Anefalos Pereira, Michael Wood, Y. G. Sharabian, Y. Ghandilyan, X. Zheng, J. Zhang, D. S. Carman, M. Ungaro, and E. Long

Subjects
Physics, Particle physics, 010308 nuclear & particles physics, Scattering, Cherenkov detector, media_common.quotation_subject, Electron, 01 natural sciences, Resonance (particle physics), Asymmetry, law.invention, Nuclear physics, law, 0103 physical sciences, Isobar, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Spin-½, media_common
Abstract

We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.

Published
2016

25. Recent results on nucleon resonance electrocouplings from the studies of π + π − p electroproduction with the CLAS detector

Author

V. I Mokeev, V. D Burkert, L Elouadrhiri, G. V Fedotov, E. N Golovach, and B. S Ishkhanov

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Proton, Hadron, Detector, Astronomy and Astrophysics, Resonance (particle physics), High Energy Physics - Experiment, Excited state, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, Nucleon, Instrumentation
Abstract

Recent results on nucleon resonance studies in $\pi^{+}\pi^{-}p$ electro- production off protons with the CLAS detector are presented. The analysis of CLAS data allowed us to determine all essential contributing mechanisms, providing a credible separation between resonant and non-resonant parts of the cross sections in a wide kinematical area of invariant masses of the final hadronic system $1.3, Comment: 7 pages, 5 figures, NSTAR 2009 conference

Published
2009

26. Moments of the spin structure functions g1p and g1d for 0.05<Q2<3.0 GeV2

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Chiral perturbation theory, Heavy baryon chiral perturbation theory, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hadron, 01 natural sciences, Baryon, Nuclear physics, Polarizability, 0103 physical sciences, Sum rule in quantum mechanics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The spin structure functions g 1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q 2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH3 and ND3 targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for 0.05 Q 2 5 GeV 2 and W 3 GeV . The first moments of g 1 for the proton and deuteron are presented – both have a negative slope at low Q 2 , as predicted by the extended Gerasimov–Drell–Hearn sum rule. The first extraction of the generalized forward spin polarizability of the proton γ 0 p is also reported. This quantity shows strong Q 2 dependence at low Q 2 . Our analysis of the Q 2 evolution of the first moment of g 1 shows agreement in leading order with Heavy Baryon Chiral Perturbation Theory. However, a significant discrepancy is observed between the γ 0 p data and Chiral Perturbation calculations for γ 0 p , even at the lowest Q 2 .

Published
2009

27. Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions

Author

H S, Jo, F X, Girod, H, Avakian, V D, Burkert, M, Garçon, M, Guidal, V, Kubarovsky, S, Niccolai, P, Stoler, K P, Adhikari, D, Adikaram, M J, Amaryan, M D, Anderson, S, Anefalos Pereira, J, Ball, N A, Baltzell, M, Battaglieri, V, Batourine, I, Bedlinskiy, A S, Biselli, S, Boiarinov, W J, Briscoe, W K, Brooks, D S, Carman, A, Celentano, S, Chandavar, G, Charles, L, Colaneri, P L, Cole, N, Compton, 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, G, Fedotov, S, Fegan, A, Filippi, J A, Fleming, B, Garillon, N, Gevorgyan, Y, Ghandilyan, G P, Gilfoyle, K L, Giovanetti, J T, Goetz, E, Golovatch, R W, Gothe, K A, Griffioen, B, Guegan, N, Guler, L, Guo, K, Hafidi, H, Hakobyan, N, Harrison, M, Hattawy, K, Hicks, N, Hirlinger Saylor, D, Ho, M, Holtrop, S M, Hughes, Y, Ilieva, D G, Ireland, B S, Ishkhanov, D, Jenkins, K, Joo, S, Joosten, D, Keller, G, Khachatryan, M, Khandaker, A, Kim, W, Kim, A, Klein, F J, Klein, S E, Kuhn, S V, Kuleshov, P, Lenisa, K, Livingston, H Y, Lu, I J D, MacGregor, B, McKinnon, Z E, Meziani, M, Mirazita, V, Mokeev, R A, Montgomery, H, Moutarde, A, Movsisyan, E, Munevar, C, Munoz Camacho, P, Nadel-Turonski, L A, Net, G, Niculescu, M, Osipenko, A I, Ostrovidov, M, Paolone, K, Park, E, Pasyuk, J J, Phillips, S, Pisano, O, Pogorelko, J W, Price, S, Procureur, Y, Prok, A J R, Puckett, B A, Raue, M, Ripani, A, Rizzo, G, Rosner, P, Rossi, P, Roy, F, Sabatié, C, Salgado, D, Schott, R A, Schumacher, E, Seder, A, Simonyan, Iu, Skorodumina, G D, Smith, D, Sokhan, N, Sparveris, S, Stepanyan, I I, Strakovsky, S, Strauch, V, Sytnik, Ye, Tian, S, Tkachenko, M, Ungaro, H, Voskanyan, E, Voutier, N K, Walford, D P, Watts, X, Wei, L B, Weinstein, M H, Wood, N, Zachariou, L, Zana, J, Zhang, Z W, Zhao, I, Zonta, 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), Thomas Jefferson National Accelerator Facility (Jefferson Lab), 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, Rensselaer Polytechnic Institute (RPI), Old Dominion University [Norfolk] (ODU), Argonne National Laboratory [Lemont] (ANL), Universidad Tecnica Federico Santa Maria [Valparaiso] (UTFSM), University of Connecticut (UCONN), Ohio University, Carnegie Mellon University [Pittsburgh] (CMU), CLAS Collaboration, and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Particle physics, Photon, Proton, HERA, General Physics and Astronomy, Socio-culturale, FOS: Physical sciences, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, High Energy Physics - Experiment (hep-ex), CLAS, virtual compton scattering, Twist, Nuclear Experiment (nucl-ex), VIRTUAL COMPTON-SCATTERING, NUCLEON, Nuclear Experiment, Quantum chromodynamics, Physics, 3. Good health, Phase space, virtual compton scattering, nucleon, High Energy Physics::Experiment, Nucleon
Abstract

Unpolarized and beam-polarized four-fold cross sections $\frac{d^4 \sigma}{dQ^2 dx_B dt d\phi}$ for the $ep\to e^\prime p^\prime \gamma$ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 ($Q^2,x_B,t$) bins over the widest phase space ever explored in the valence-quark region. Several models of Generalized Parton Distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD $H$, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton Form Factors, these results reveal a tomographic image of the nucleon., Comment: 7 pages, 5 figures

Published
2015

28. Measurement of the x- and Q2-dependence of the asymmetry A1 on the nucleon

Author

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

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, Quark model, Parton, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Invariant mass, 010306 general physics, Nucleon, media_common
Abstract

We report results for the virtual photon asymmetry A{sub 1} on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ({sup 15}NH{sub 3}) and deuteron ({sup 15}ND{sub 3}) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5.7 GeV. In the present paper, we concentrate on our results for A{sub 1}(x,Q{sup 2}) and the related ratio g{sub 1}/F{sub 1}(x,Q{sup 2}) in the resonance and the deep inelastic regions for our lowest and highest beam energies, covering a range in momentum transfer Q{sup 2} from 0.05 to 5.0 GeV{sup 2} and in final-state invariant mass W up to about 3 GeV. Our data show detailed structure in the resonance region, which leads to a strong Q{sup 2}--dependence of A{sub 1}(x,Q{sup 2}) for W below 2 GeV. At higher W, a smooth approach to the scaling limit, established by earlier experiments, can be seen, but A{sub 1}(x,Q{sup 2}) is not strictly Q{sup 2}--independent. We add significantly to the world data set at high x, up to x = 0.6. Our data exceed the SU(6)-symmetric quark model expectation for both the proton and the deuteron whilemore » being consistent with a negative d-quark polarization up to our highest x. This data set should improve next-to-leading order (NLO) pQCD fits of the parton polarization distributions.« less

Published
2006

29. Publisher's Note: Exclusiveπ0electroproduction atW>2GeV with CLAS [Phys. Rev. C 90, 025205 (2014)]

Author

George Davey Smith, N. A. Baltzell, D. Doughty, M. Khandaker, A. Simonyan, J. P. Ball, A. D'Angelo, Y. Prok, D. S. Carman, I. Zonta, H. Moutarde, K. L. Giovanetti, Larry Weinstein, X. Wei, H. Y. Lu, E. De Sanctis, V. P. Kubarovsky, M. Contalbrigo, Sergey Kuleshov, L. El Fassi, O. Pogorelko, D. I. Sober, D. Protopopescu, M. Garçon, E. Voutier, A. Movsisyan, N. Dashyan, Y. G. Sharabian, S. Chandavar, Frank Klein, A. V. Vlassov, F. X. Girod, D. G. Ireland, Dustin Keller, K. Livingston, C. Munoz Camacho, R. De Vita, K. P. Adhikari, V. Crede, Andrew Puckett, Lorenzo Zana, Martin K. Mayer, K. Hafidi, R. Dupre, S. Anefalos Pereira, V. Sytnik, M. Battaglieri, P. L. Cole, Z. W. Zhao, H. Hakobyan, H. S. Jo, B. McKinnon, S. Strauch, W. Kim, S. Niccolai, H. Avakian, P. Nadel-Turonski, B. Guegan, R. A. Montgomery, M. Mirazita, I. Niculescu, M. Yurov, E. Phelps, Diane Schott, H. Voskanyan, N. Gevorgyan, S. Fegan, S. Koirala, A. I. Ostrovidov, K. Park, G. V. Fedotov, W. J. Briscoe, E. Pasyuk, P. Roy, C. Djalali, A. Celentano, R. W. Gothe, M. Ripani, Volker D. Burkert, M. Guidal, A. S. Biselli, D. P. Watts, H. Egiyan, Nicholas M. Harrison, A. El Alaoui, L. Colaneri, Gerard Gilfoyle, D. Sokhan, D. G. Jenkins, W. I. Levine, M. Holtrop, Nicholas Zachariou, N. Markov, R. A. Schumacher, S. E. Kuhn, M. Hattawy, S. Pisano, Luciano Pappalardo, O. Cortes, I. Bedlinskiy, J. A. Fleming, J. Bono, K. A. Griffioen, E. L. Isupov, N. K. Walford, Andreas Klein, J. J. Phillips, Ye Tian, S. Park, P. Eugenio, Carlos A. Salgado, S. Boiarinov, P. Rossi, W. Tang, Y. Ghandilyan, Barry Ritchie, B. S. Ishkhanov, M. Osipenko, T. A. Forest, S. Stepanyan, B. Garillon, S. Procureur, P. Stoler, A. Kim, E. Seder, K. Hicks, William Brooks, I. J. D. MacGregor, W. Phelps, G. Gavalian, V. Mokeev, I. Senderovich, Alessandro Rizzo, E. Golovatch, L. Elouadrhiri, A. Deur, J. Zhang, J. W. Price, L. Guo, M. Ungaro, K. Joo, V. Batourine, F. Sabatié, C. I. Moody, P. Lenisa, and Brian Raue

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Meson production
Published
2014

30. Precision measurements ofg1of the proton and of the deuteron with 6 GeV electrons

Author

P. Lenisa, N. A. Baltzell, D. Meekins, E. De Sanctis, M. Aghasyan, C. Keith, D. I. Sober, Friedrich Klein, K. A. Griffioen, G. Rosner, M. Contalbrigo, L. Elouadrhiri, V. Crede, O. Pogorelko, Y. Ghandilyan, F. Sabatié, P. Roy, C. Smith, Diane Schott, Victor Mokeev, C. Hanretty, D. S. Carman, R. A. Montgomery, M. J. Amaryan, D. Adikaram, A. I. Ostrovidov, K. Park, K. Hicks, J. W. Price, S. Strauch, S. Fegan, H. S. Jo, H. Moutarde, S. Tkachenko, A. V. Vlassov, D. G. Ireland, G. D. Smith, S. Stepanyan, M. Holtrop, D. Protopopescu, K. Joo, W. Tang, A. Movsisyan, E. Voutier, T. Mineeva, K. L. Giovanetti, Larry Weinstein, B. Zhao, S. Pozdniakov, M. Garçon, Nicholas Kvaltine, R. A. Schumacher, I. Zonta, P. Bosted, N. Harrison, Volker D. Burkert, A. S. Biselli, S. Koirala, M. Osipenko, A. Kim, B. Guegan, S. S. Jawalkar, J. J. Phillips, R. De Vita, M. Ungaro, J. Brock, S. Anefalos Pereira, H. Voskanyan, Y. Prok, W. Gohn, S. Bültmann, K. Hafidi, Y. G. Sharabian, C. Carlin, R. G. Fersch, I. I. Strakovsky, S. S. Stepanyan, I. J. D. MacGregor, Andrew Puckett, T. A. Forest, V. Sytnik, P. L. Cole, B. Garillon, K. Livingston, Jie Zhang, Martin K. Mayer, R. W. Gothe, A. Deur, N. Kalantarians, Gerard Gilfoyle, J. Pierce, Avraham Klein, B. Vernarsky, Y. Ilieva, N. K. Walford, S. Chandavar, W. Kim, N. Guler, G. Niculescu, D. Sokhan, L. Colaneri, M. S. Saini, W. J. Briscoe, J. Bono, P. Nadel-Turonski, D. Doughty, Chaden Djalali, B. S. Ishkhanov, L. El Fassi, D. Keller, N. Markov, M. Taiuti, P. Rossi, S. Pisano, A. Simonyan, Sergey Kuleshov, R. Paremuzyan, G. E. Dodge, H. Y. Lu, M. Mirazita, P. Peng, H. Avakian, C. Munoz Camacho, A. El Alaoui, W. K. Brooks, F. X. Girod, Z. W. Zhao, D. P. Watts, I. Niculescu, B. McKinnon, N. Gevorgyan, D. Ho, J. P. Ball, M. Khandaker, Nicholas Zachariou, M. Ripani, L. L. Pappalardo, V. P. Kubarovsky, Andrea Celentano, S. E. Kuhn, A. Rizzo, D. Rimal, S. Procureur, J. A. Fleming, E. Munevar, Annalisa D'Angelo, S. Niccolai, D. G. Crabb, B. A. Raue, N. Dashyan, M. Battaglieri, H. Baghdasaryan, Lorenzo Zana, G. V. Fedotov, K. P. Adhikari, X. Jiang, E. Seder, M. Hattawy, C. Salgado, J. T. Goetz, O. Cortes, E. L. Isupov, R. Dupre, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), CLAS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Particle physics, FOS: Physical sciences, SPIN STRUCTURE, INELASTIC EP, SCATTERING, NUCLEON, CLAS, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Settore FIS/04 - Fisica Nucleare e Subnucleare, NO, Nuclear physics, Invariant mass, Nuclear Experiment (nucl-ex), Nuclear Experiment, Quantum chromodynamics, Physics, Scattering, Polarization (waves), Deuterium, Quark–gluon plasma, High Energy Physics::Experiment, Nucleon
Abstract

The inclusive polarized structure functions of the proton and deuteron, g(1)(p) and g(1)(d) , were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at laboratory angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual deep inelastic region kinematics, Q(2) > 1 GeV2 and the final-state invariant mass W > 2 GeV, the ratio of polarized to unpolarized structure functions g(1)/F-1 is found to be nearly independent of Q(2) at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative quantum chromodynamics, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.

Published
2014

31. Publisher's Note: Beam asymmetryΣforπ+andπ0photoproduction on the proton for photon energies from 1.102 to 1.862 GeV [Phys. Rev. C88, 065203 (2013)]

Author

L. Elouadrhiri, N. A. Baltzell, I. I. Strakovsky, C. S. Nepali, George Davey Smith, A. Deur, M. Contalbrigo, R. Paremuzyan, S. Fegan, D. Adikaram, M. Guidal, F. X. Girod, E. De Sanctis, A. D'Angelo, V. Mokeev, G. Niculescu, M. Khandaker, W. Tang, M. Aghasyan, M. Osipenko, Nicholas M. Harrison, Gerard Gilfoyle, M. Holtrop, D. I. Sober, A. El Alaoui, Nicholas Zachariou, L. El Fassi, D. Martinez, I. J. D. MacGregor, S. Park, D. Sokhan, S. Strauch, N. Dashyan, Luciano Pappalardo, P. Nadel-Turonski, P. Rossi, D. Rimal, I. Zonta, C. Djalali, A. Celentano, R. W. Gothe, D. P. Watts, W. Gohn, H. Y. Lu, S. Koirala, H. Egiyan, M. J. Amaryan, K. Livingston, Frank Klein, D. G. Ireland, Dustin Keller, Yordanka Ilieva, Diane Schott, E. Munevar, A. I. Ostrovidov, K. Park, R. De Vita, B. S. Ishkhanov, Michael Dugger, Sergey Kuleshov, Yakov I. Azimov, Brian Raue, H. Moutarde, V. Crede, E. Golovatch, A. Kubarovsky, K. A. Griffioen, N. K. Walford, I. Niculescu, N. Guler, K. L. Giovanetti, J. J. Phillips, K. Hafidi, S. Anefalos Pereira, R. A. Montgomery, P. Stoler, Ron L. Workman, V. Batourine, D. Doughty, G. Rosner, P. L. Cole, Z. W. Zhao, Volker D. Burkert, A. S. Biselli, R. A. Schumacher, S. Niccolai, D. Heddle, J. P. Ball, Y. Prok, D. S. Carman, F. Sabatié, K. Hicks, C. Hanretty, J. Zhang, S. Chandavar, S. Tkachenko, T. Mineeva, D. Protopopescu, J. W. Price, H. Avakian, P. Peng, B. Torayev, S. Pozdniakov, I. Senderovich, Alessandro Rizzo, E. Voutier, L. Guo, M. Ungaro, C. Munoz Camacho, S. Stepanyan, I. Bedlinskiy, Andreas Klein, M. Ripani, A. Kim, B. McKinnon, H. Voskanyan, K. Joo, Carlos A. Salgado, M. Mirazita, E. Phelps, W. J. Briscoe, E. Pasyuk, N. Gevorgyan, S. Procureur, S. Pisano, R. Dupre, M. Battaglieri, J. A. Fleming, V. P. Kubarovsky, P. Collins, O. Pogorelko, S. Lewis, Martin K. Mayer, M. S. Saini, J. T. Goetz, H. Seraydaryan, Y. G. Sharabian, P. Eugenio, M. Taiuti, D. Ho, E. Seder, Barry Ritchie, O. Cortes, E. L. Isupov, Ye Tian, S. Boiarinov, G. V. Fedotov, D. P. Weygand, K. P. Adhikari, Lorenzo Zana, H. Hakobyan, H. S. Jo, and W. Kim

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Meson production, Photon, Proton, Partial wave analysis, media_common.quotation_subject, Asymmetry, Beam (structure), media_common
Published
2014

32. Exclusive π0 electroproduction at W>2 GeV with CLAS

Author

I. BedlinskiyInstitute of Theoretical and Experimental Physics, V. Kubarovsky(Thomas Jefferson National Accelerator Facility), S. Niccolai(Institut de Physique Nucléaire ORSAY), P. Stoler(Rensselaer Polytechnic Institute), K. P. Adhikari(Old Dominion University), M. D. Anderson(University of Glasgow), S. Anefalos Pereira(INFN), H. Avakian(Thomas Jefferson National Accelerator Facility), J. Ball(CEA), N. A. Baltzell(Argonne National Laboratory), M. Battaglieri(INFN), V. Batourine(Thomas Jefferson National Accelerator Facility), A. S. Biselli(Thomas Jefferson National Accelerator Facility), S. Boiarinov(Thomas Jefferson National Accelerator Facility), J. Bono(Florida International University), W. J. Briscoe(The George Washington University), W. K. Brooks(Universidad Técnica Federico Santa María), V. D. Burkert(Thomas Jefferson National Accelerator Facility), D. S. Carman(Thomas Jefferson National Accelerator Facility), A. Celentano(INFN), S. Chandavar(Ohio University), L. Colaneri(INFN), P. L. Cole(Idaho State University), M. Contalbrigo(INFN), O. Cortes(Idaho State University), V. Crede(Florida State University), A. D'Angelo(INFN), N. Dashyan(Yerevan Physics Institute), R. De Vita(INFN), E. De Sanctis(INFN), A. Deur(Thomas Jefferson National Accelerator Facility), C. Djalali(University of South Carolina), D. Doughty(Christopher Newport University), R. Dupre(Institut de Physique Nucléaire ORSAY), H. Egiyan(Thomas Jefferson National Accelerator Facility), A. El Alaoui(Argonne National Laboratory), L. El Fassi(Old Dominion University), L. Elouadrhiri(Thomas Jefferson National Accelerator Facility), P. Eugenio(Florida State University), G. Fedotov(University of South Carolina), S. Fegan(INFN), J. A. Fleming(Edinburgh University), T. A. Forest(Idaho State University), B. Garillon(Institut de Physique Nucléaire ORSAY), M. Gar\c con(CEA), G. Gavalian(Old Dominion University), N. Gevorgyan(Yerevan Physics Institute), Y. Ghandilyan(Yerevan Physics Institute), G. P. Gilfoyle(University of Richmond), K. L. Giovanetti(James Madison University), F. X. Girod(Thomas Jefferson National Accelerator Facility), E. Golovatch(Skobeltsyn Institute of Nuclear Physics), R. W. Gothe(University of South Carolina), K. A. Griffioen(Institut de Physique Nucléaire ORSAY), B. Guegan(Institut de Physique Nucléaire ORSAY), L. Guo(Florida International University), K. Hafidi(Argonne National Laboratory), H. Hakobyan(Universidad Técnica Federico Santa María), N. Harrison(University of Connecticut), M. Hattawy(Institut de Physique Nucléaire ORSAY), K. Hicks(Ohio University), M. Holtrop(University of New Hampshire), D. G. Ireland(University of Glasgow), B. S. Ishkhanov(Skobeltsyn Institute of Nuclear Physics), E. L. Isupov(Skobeltsyn Institute of Nuclear Physics), D. Jenkins(Institut de Physique Nucléaire ORSAY), H. S. Jo(Institut de Physique Nucléaire ORSAY), K. Joo(University of Connecticut), D. Keller(University of Virginia), M. Khandaker(Idaho State University), A. Kim(University of Connecticut), W. Kim(Kyungpook National University), A. Klein(Old Dominion University), F. J. Klein(Catholic University of America), S. Koirala(Old Dominion University), S. E. Kuhn(Old Dominion University), S. V. Kuleshov(Universidad Técnica Federico Santa María), P. Lenisa(INFN), W. I. Levine(Carnegie Mellon University), K. Livingston(University of Glasgow), H. Y. Lu(University of South Carolina), I . J . D. MacGregor(University of Glasgow), N. Markov(University of Connecticut), M. Mayer(Old Dominion University), B. McKinnon(University of Glasgow), M. Mirazita(INFN), V. Mokeev(Thomas Jefferson National Accelerator Facility), R. A. Montgomery(INFN), C. I. Moody(Argonne National Laboratory), H. Moutarde(CEA), A Movsisyan(INFN), C. Munoz Camacho(Institut de Physique Nucléaire ORSAY), P. Nadel-Turonski(Thomas Jefferson National Accelerator Facility), I. Niculescu(James Madison University), M. Osipenko(INFN), A. I. Ostrovidov(Florida State University), L. L. Pappalardo(INFN), K. Park(Thomas Jefferson National Accelerator Facility), S. Park(Florida State University), E. Pasyuk(Thomas Jefferson National Accelerator Facility), E. Phelps(University of South Carolina), W. Phelps(Florida International University), J. J. Phillips(University of Glasgow), S. Pisano(INFN), O. Pogorelko(Institute of Theoretical and Experimental Physics), J. W. Price(California State University), Y. Prok(Old Dominion University), D. Protopopescu(University of Glasgow), S. Procureur(CEA), A. J. R. Puckett(University of Connecticut), B. A. Raue(Florida International University), M. Ripani(INFN), B. G. Ritchie(Arizona State University), A. Rizzo(INFN), P. Rossi(INFN), P. Roy(Florida State University), F. Sabatié(CEA), C. Salgado(Norfolk State University), D. Schott(The George Washington University), R. A. Schumacher(Carnegie Mellon University), E. Seder(University of Connecticut), I. Senderovich(Arizona State University), Y. G. Sharabian(Thomas Jefferson National Accelerator Facility), A. Simonyan(Yerevan Physics Institute), G. D. Smith(Edinburgh University), D. I. Sober(Catholic University of America), D. Sokhan(University of Glasgow), S. S. Stepanyan(Kyungpook National University), S. Strauch(University of South Carolina), V. Sytnik(Universidad Técnica Federico Santa María), W. Tang(Ohio University), Ye Tian(University of South Carolina), M. Ungaro(Thomas Jefferson National Accelerator Facility), A. V. Vlassov(Institute of Theoretical and Experimental Physics), H. Voskanyan(Yerevan Physics Institute), E. Voutier(LPSC), N. K. Walford(Catholic University of America), D. Watts(University of Glasgow), X. Wei(Thomas Jefferson National Accelerator Facility), L. B. Weinstein(Old Dominion University), M. Yurov(University of Virginia), N. Zachariou(University of South Carolina), L. Zana(Edinburgh University), J. Zhang(Thomas Jefferson National Accelerator Facility), Z. W. Zhao(University of Virginia), I. Zonta(INFN), and for the CLAS Collaboration()

Subjects
hep-ex, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, NO
Abstract

Exclusive neutral-pion electroproduction ($ep\to e^\prime p^\prime \pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\pi$ and structure functions $\sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$ as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The 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.

Published
2014

33. Theep→e′pηReaction at and above theS11(1535)Baryon Resonance

Author

M. J. Amaryan, M. Taiuti, S. K. Matthews, J. Ficenec, Gyurjyan, W. Kim, A. Longhi, R. A. Schumacher, B. E. Bonner, L. Elouadrhiri, A. P. Freyberger, R. Magahiz, Robert E. Welsh, S. Dytman, S. Whisnant, B. M. Preedom, Federico Ronchetti, R. J. Feuerbach, K. L. Giovanetti, B. Asavapibhop, Michael Dugger, Shalev Gilad, De Sanctis E, A. V. Vlassov, G. Ricco, J. R. Kane, H. Avakian, Philip L. Cole, J. P. Cummings, G. S. Adams, Larry Weinstein, R. A. Miskimen, K. Joo, J. Shaw, R. W. Major, Moshe Gai, M. Kossov, W. J. Briscoe, D. Rowntree, D. Doughty, K. Beard, W. K. Brooks, Friedrich Klein, R. S. Hicks, Brian Raue, Kevin Fissum, Kalvir S. Dhuga, Barry Ritchie, A. Coleman, K. A. Griffioen, M. M. Ito, G. Riccardi, L. M. Qin, J. J. Manak, M. Mirazita, J. M. Laget, C. E. Hyde-Wright, J. W C McNabb, M. S. Ohandjanyan, D. Heddle, C. Salgado, H. R. Weller, Roy Thompson, Curtis Smith, D. P. Weygand, Herbert O. Funsten, S. A. Philips, Patrick Girard, Y. Kuang, H. Egiyan, M. Witkowski, Bernhard Mecking, Mestayer, A. J. Sarty, Jing Zhao, S. Stepanyan, De Vita R, D. G. Jenkins, C. Djalali, Z. L. Zhou, M. Lucas, Airton Deppman, D. I. Sober, A. Shafi, D. Hancock, Avraham Klein, Leskin Ga, M. Battaglieri, S. McAleer, William Bertozzi, E. Polli, E. Anciant, L. Farhi, G. E. Dodge, Daniel S. Carman, V. B. Gavrilov, O. Pogorelko, A. K. Opper, G. Audit, J. W. Price, M. Khandaker, E. Wolin, P. V. Degtyarenko, Y. Patois, Gerard Gilfoyle, Dinko Pocanic, L.C. Dennis, K. Loukachine, N. Pivnyuk, M. Bektasoglu, S. E. Kuhn, S. M. Shuvalov, D. Lawrence, M. Eckhause, J. Napolitano, M. Ripani, M. Guillo, Jochen Heisenberg, Y. V. Efremenko, Volker D. Burkert, M. Sanzone, J. Connelly, Donal Day, M. Sargsyan, G. A. Peterson, M. Guidal, A. V. Skabelin, J. Yun, D. Cords, A. Yegneswaran, A. S. Biselli, Elton Smith, S. Barrow, M. Holtrop, Thomas E. Smith, G. S. Mutchler, M. Anghinolfi, Hall Crannell, D. G. Crabb, James Mueller, S. Taylor, P. D. Rubin, G. Capitani, F. Roudot, D. J. Tedeschi, Y. G. Sharabian, M. Spraker, Sapunenko, R. C. Minehart, M. Klusman, Nicola Bianchi, S. Boiarinov, C. A. Meyer, J. S. McCarthy, B. Carnahan, Thierry Auger, A. R. Reolon, Michael Vineyard, C. Marchand, P. Rossi, P. Dragovitsch, F. W. Hersman, R. A. Demirchyan, T. Y. Tung, J. Hardie, K. Y. Kim, Muccifora, R. A. Niyazov, John T. O'Brien, P. Corvisiero, K. S. Egiyan, Calarco, P. Stoler, and K. Hicks

Subjects
Baryon, Physics, Nuclear physics, Particle physics, Photon, Amplitude, Angular distribution, Meson, Momentum transfer, General Physics and Astronomy, Resonance, Invariant (physics), Nuclear Experiment
Abstract

New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.

Published
2001

34. The time-of-flight system for CLAS

Author

Elton Smith, K. Loukachine, A. D. Hancock, C. Marchand, J. Distelbrink, L. C. Smith, W. Kim, T.Y. Tung, J. Ficenec, K. MacArthur, G. S. Mutchler, Andrew G. Weisenberger, D. Schutt, Bernhard Mecking, L. Elouadrhiri, Robert E. Welsh, D. A. Jenkins, T. Carstens, F. W. Hersman, M. Guidal, M. Holtrop, Susan Taylor, H. Egiyan, T. P. Smith, and M. Eckhause

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, Cosmic ray, Particle accelerator, Particle identification, Particle detector, Linear particle accelerator, law.invention, Nuclear physics, Time of flight, law, Scintillation counter, Instrumentation
Abstract

The time-of-flight system for the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility is described. The system, covering an area of 206-square-meters, is composed of scintillation counters 5.08 cm thick, 15 and 22 cm wide, and lengths which vary from 32 cm at the most forward angle to 450 cm at larger angles. All of the components of the system have been designed to optimize the time resolution. Event timing, achieved by leading-edge discrimination with time-walk correction, has been measured with cosmic rays, a laser pulser, and known particle interactions. The intrinsic time resolution varies from about 80 ps for the short counters to 160 ps for the longer counters. Reconstruction of interacting particles during the first period of operation yields an average time resolution for electrons of 163 ps.

Published
1999

35. E1+M1+andS1+M1+from an Analysis ofp(e, e′p)π0in the Region of theΔ(1232)Resonance atQ2=3.2(GeV/c)2

Author

Volker D. Burkert and L. Elouadrhiri

Subjects
Quantum chromodynamics, Physics, Particle physics, Magnetic dipole transition, Quark model, Quadrupole, Scalar (mathematics), Momentum transfer, General Physics and Astronomy, Perturbative QCD, High Energy Physics::Experiment, Magnetic dipole
Abstract

We have analyzed exclusive $p(e, {e}^{\ensuremath{'}}p){\ensuremath{\pi}}^{0}$ data to determine the electromagnetic and scalar transition multipoles in the mass region of the $\ensuremath{\Delta}(1232)$ at the highest ${Q}^{2}$ value where data exist. The ratio of the electric quadrupole and the magnetic dipole transition moments is determined to be $\frac{{E}_{1+}}{{M}_{1+}}=0.06\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.03$, and for the scalar quadrupole transition we find $\frac{{S}_{1+}}{{M}_{1+}}=0.07\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.03$. The results rule out that perturbative QCD governs the dynamics of the ${\ensuremath{\gamma}}_{v}p\ensuremath{\Delta}$ transition at such ${Q}^{2}$. They are more consistent with predictions of relativistic extensions of the nonrelativistic constituent quark model.

Published
1995

36. Publisher’s Note: Measurement of the NeutronF2Structure Function via Spectator Tagging with CLAS [Phys. Rev. Lett.108, 142001 (2012)]

Author

C. E. Hyde, D. G. Ireland, V. Crede, D. Protopopescu, S. Pozdniakov, H. C. Fenker, D. Adikaram, M. Guidal, Nicholas Kvaltine, G. Niculescu, P. Stoler, Wolodymyr Melnitchouk, G. V. Fedotov, N. Kalantarians, B. Dey, K. Hicks, A. Celentano, R. W. Gothe, M. J. Amaryan, H. Avakian, M. Holtrop, D. P. Weygand, E. De Sanctis, A. Daniel, A. El Alaoui, E. L. Isupov, M. Aghasyan, Luciano Pappalardo, B. Guegan, D. I. Sober, H. Moutarde, M. Contalbrigo, W. Kim, G. Charles, M. Ripani, S. Fegan, K. L. Giovanetti, C. E. Keppel, S. Bültmann, E. Seder, W. J. Briscoe, E. Pasyuk, Larry Weinstein, D. Rimal, Alexei V. Klimenko, D. Doughty, P. Khetarpal, P. E. Bosted, Carlos A. Salgado, Andreas Klein, K. Livingston, M. Ispiryan, Michael Vineyard, D. Heddle, K. P. Adhikari, S. Park, Brian Raue, N. Baillie, Y. Prok, D. S. Carman, B. Zhao, Lorenzo Zana, N. Guler, P. Rossi, H. S. Jo, B. McKinnon, W. Tang, S. E. Kuhn, P. Eugenio, M. Taiuti, R. De Vita, E. Voutier, M. Osipenko, N. Dashyan, D. Branford, V. P. Kubarovsky, M. Khandaker, F. Sabatié, S. S. Jawalkar, S. Niccolai, M. Gabrielyan, N. Gevorgyan, Frank Klein, I. J. D. MacGregor, Sergey Kuleshov, Yordanka Ilieva, M. Anghinolfi, S. Tkachenko, Y. G. Sharabian, S. Anefalos Pereira, Michael Wood, E. V. Hungerford, K. Hafidi, Gerard Gilfoyle, G. Ricco, F. X. Girod, D. Sokhan, M. S. Saini, T. Mineeva, M. E. Christy, Diane Schott, A. I. Ostrovidov, K. Park, Hovhannes Baghdasaryan, S. Strauch, Volker D. Burkert, A. S. Biselli, J. Domingo, A. Fradi, S. Pisano, B. Morrison, C. Djalali, K. A. Griffioen, Dipangkar Dutta, L. Guo, M. Ungaro, J. Arrington, R. A. Schumacher, L. Graham, S. S. Stepanyan, R. Dupre, M. Battaglieri, S. Stepanyan, William Brooks, Rolf Ent, G. E. Dodge, H. Y. Lu, S. Procureur, I. Niculescu, A. Kim, J. Zhang, G. Rosner, Y. Mao, S. Chandavar, J. W. Price, A. Ni, V. Tvaskis, D. P. Watts, H. Egiyan, P. Nadel-Turonski, N. Markov, E. Munevar, P. M. King, E. Golovatch, W. Gohn, L. Elouadrhiri, A. Deur, P. L. Cole, A. D'Angelo, and L. El Fassi

Subjects
Physics, Nuclear physics, Structure function, General Physics and Astronomy, Neutron
Published
2012

37. Publisher’s Note: Branching ratio of the electromagnetic decay of theΣ+(1385)Phys. Rev. D85, 052004 (2012)

Author

D. Keller, K. Hicks, K. P. Adhikari, D. Adikaram, M. J. Amaryan, M. Anghinolfi, H. Baghdasaryan, J. Ball, M. Battaglieri, I. Bedlinskiy, A. S. Biselli, C. Bookwalter, S. Boiarinov, D. Branford, W. J. Briscoe, W. K. Brooks, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, P. L. Cole, M. Contalbrigo, V. Crede, A. D’Angelo, A. Daniel, N. Dashyan, R. De Vita, E. De Sanctis, C. Djalali, D. Doughty, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, M. Y. Gabrielyan, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, W. Gohn, E. Golovatch, R. W. Gothe, L. Graham, K. A. Griffioen, M. Guidal, N. Guler, L. Guo, K. Hafidi, H. Hakobyan, M. Holtrop, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, H. S. Jo, K. Joo, M. Khandaker, P. Khetarpal, A. Kim, W. Kim, F. J. Klein, A. Kubarovsky, V. Kubarovsky, S. V. Kuleshov, H. Y. Lu, I. J. D. MacGregor, Y. Mao, N. Markov, M. Mayer, B. McKinnon, C. A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, H. Moutarde, E. Munevar, P. Nadel-Turonski, R. Nasseripour, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, L. Pappalardo, R. Paremuzyan, K. Park, S. Park, E. Pasyuk, S. Anefalos Pereira, S. Pisano, O. Pogorelko, S. Pozdniakov, S. Procureur, Y. Prok, D. Protopopescu, B. A. Raue, G. Ricco, D. Rimal, M. Ripani, B. G. Ritchie, G. Rosner, P. Rossi, F. Sabatié, M. S. Saini, C. Salgado, D. Schott, R. A. Schumacher, H. Seraydaryan, Y. G. Sharabian, E. S. Smith, G. D. Smith, D. I. Sober, D. Sokhan, S. S. Stepanyan, S. Stepanyan, P. Stoler, S. Strauch, M. Taiuti, W. Tang, C. E. Taylor, S. Tkachenko, B. Vernarsky, M. F. Vineyard, A. V. Vlassov, H. Voskanyan, E. Voutier, D. P. Watts, M. H. Wood, N. Zachariou, L. Zana, B. Zhao, and Z. W. Zhao

Subjects
Nuclear and High Energy Physics
Published
2012

38. Measurements of the (e,e’pπ−) reaction on nuclei in the nucleon resonance region

Author

P. V. Degtyarenko, F. S. Dietrich, S. O. Melnikoff, R. A. Miskimen, S.M. Shuvalov, G. A. Peterson, V. Gavrilov, K. van Bibber, L. Elouadrhiri, K. Wang, J. D. Molitoris, and J. Button-Shafer

Subjects
Nuclear reaction, Physics, Nuclear physics, Baryon, Nuclear and High Energy Physics, Meson, Hadron, Resonance, Atomic physics, Inelastic scattering, Nucleon, Delta baryon
Published
1994

39. Multiple hadron production by 14.5 GeV electron and positron scattering from nuclear targets

Author

S. O. Melnikoff, R. A. Miskimen, Bibber Kv, M. V. Kossov, V. Gavrilov, F. S. Dietrich, J. Button-Shafer, G.A. Leksin, S.M. Shuvalov, J. D. Molitoris, G. A. Peterson, K. Wang, Degtyarenko Pv, and L. Elouadrhiri

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Proton, Nuclear Theory, Hadron, Charged particle, Baryon, Nuclear physics, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, Nucleon
Abstract

Multiple proton and pion electroproduction from nuclei are studied. Final states including at least two protons produced by the interaction of 14.5 GeV electrons and positrons with light nuclei (mainly $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$) have been measured, and compared with analogous data from $^{40}\mathrm{Ar}$. Scattered electrons and positrons were detected in the energy transfer range from 0.2 to 12.5 GeV, and four-momentum transfer squared range from 0.1 to 5.0 ${\mathrm{GeV}}^{2}$/${\mathit{c}}^{2}$. Phenomenological characteristics of the secondary hadron production cross sections such as temperature and velocity of the effective source of hadrons were found to be dependent on energy transfer to the nucleus and independent on the four-momentum transfer squared at energy transfers greater than 2 GeV.

Published
1994

40. Precise Measurement of the Neutron Magnetic Form FactorGMnin the Few-GeV2Region

Author

R. J. Feuerbach, J. P. Cummings, L. C. Smith, E. Munevar, R. De Masi, D. Keller, M. Kossov, B. S. Ishkhanov, I. Popa, K. S. Egiyan, G. Ricco, K. Mikhailov, L. Cheng, M. Khandaker, M. Garçon, J. Shaw, Michael Wood, P. Nadel-Turonski, Nikolay Shvedunov, M. R. Niroula, K. Hafidi, R. Nasseripour, S. McAleer, Friedrich Klein, B. P. Quinn, Brian Raue, V. S. Serov, L. Casey, F. X. Girod, Susan Taylor, Marco A. Huertas, M. Lowry, V. Sapunenko, D. P. Watts, L. C. Dennis, B. E. Bonner, Hartmuth Arenhövel, Dinko Pocanic, H. Egiyan, R. G. Fersch, H. Avakian, D. Doughty, B. B. Niczyporuk, G. S. Adams, S. Park, D. Sharov, N. Kalantarians, P. L. Cole, Sylvain Bouchigny, Sabine Jeschonnek, R. C. Minehart, Kei Moriya, D. Heddle, P. Rossi, J. Lachniet, H. G. Juengst, C. A. Meyer, N. Pivnyuk, K. Joo, W. J. Briscoe, B. L. Berman, A. Tkabladze, G. V. Fedotov, E. Pasyuk, D. Rowntree, A. Coleman, L. M. Qin, M. Y. Gabrielyan, S. E. Kuhn, S. A. Dytman, V. Crede, Y. Ilieva, J. R. Calarco, T. Mineeva, J. W. Price, M. J. Amaryan, C. Paterson, S. Strauch, M. MacCormick, A.V. Stavinsky, M. Klusman, I. Hleiqawi, V. P. Kubarovsky, K. P. Adhikari, S. L. Careccia, A. Empl, L. El Fassi, O. Pogorelko, B. Moreno, D. P. Weygand, J. Salamanca, R. Suleiman, M. E. McCracken, Elton Smith, K. L. Giovanetti, B. Asavapibhop, G. V. O'Rielly, Tsutomu Mibe, Larry Weinstein, Z. W. Zhao, J. W C McNabb, D. J. Tedeschi, D. Protopopescu, D. G. Jenkins, Barry Ritchie, M. Anghinolfi, James Mueller, S. Malace, S. A. Morrow, P. Rubin, I. Bedlinskiy, G. S. Mutchler, Konstantin Stopani, S. Pozdniakov, V. Gyurjyan, M. M. Ito, C. Djalali, Y. G. Sharabian, G. Rosner, T. Kageya, K. Livingston, D. S. Dale, X. Wei, R. Dickson, V. Kuznetsov, C. E. Hyde-Wright, H. Denizli, N. Guler, N. A. Baltzell, P. Mattione, K. A. Griffioen, M. S. Saini, A. V. Skabelin, P. Dragovitsch, J. Zhang, S. Barrow, E. De Sanctis, S. Niccolai, J. T. Goetz, E. Polli, H. Bagdasaryan, R. A. Miskimen, J. D. Kellie, B. McKinnon, Sergey Kuleshov, M. Bektasoglu, J. Hardie, M. Nozar, W. Kim, Laird Kramer, G. Niculescu, D. I. Sober, D. Branford, M. Guidal, R. A. Schumacher, H. Hakobyan, M. Mirazita, P. Khetarpal, C. Hanretty, J. M. Laget, M. Holtrop, Victor Mokeev, L. Graham, J. R. Johnstone, N. Gevorgyan, L. Guo, M. Ungaro, M. Osipenko, F. Sabatié, A. Daniel, K. Beard, Kalvir S. Dhuga, S. Bültmann, A. I. Ostrovidov, J. Yun, D. Cords, V. Batourine, T. A. Forest, A. Yegneswaran, A. C S Lima, A. Sandorfi, K. Park, R. Fatemi, S. Stepanyan, A. V. Vlassov, D. G. Ireland, Volker D. Burkert, A. S. Biselli, J. Pierce, Avraham Klein, B. Zhao, J. Langheinrich, R. De Vita, A. Fradi, S. S. Stepanyan, S. A. Philips, William Brooks, N. Markov, P. Konczykowski, B. E. Stokes, J. J. Manak, S. Anefalos Pereira, G. E. Dodge, H. Y. Lu, N. Dashyan, Maryam Moteabbed, P. V. Degtyarenko, K. V. Dharmawardane, I. Niculescu, D. Lawrence, D. Schott, F. W. Hersman, M. Battaglieri, N. Baillie, P. Stoler, K. Hicks, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, R. Bradford, B. A. Mecking, K. Lukashin, E. Wolin, Gerard Gilfoyle, M. Guillo, D. Sokhan, W. Gohn, N. Hassall, M. Bellis, E. Golovatch, J. P. Ball, J. Hu, Y. Prok, D. S. Carman, S. Dhamija, M. D. Mestayer, L. Elouadrhiri, I. I. Strakovsky, E. L. Isupov, R. W. Gothe, G. Gavalian, S. Tkachenko, A. Deur, Michael L. Williams, J. Kuhn, N. Benmouna, J. P. Santoro, Andrei Afanasev, M. Ripani, D. G. Crabb, K. Y. Kim, Roy Thompson, Cynthia Marie Hadjidakis, S. Boiarinov, Michael Dugger, B. M. Preedom, Douglas Higinbotham, M. Yurov, Lorenzo Zana, H. S. Jo, C. Bookwalter, C. Salgado, Kwangsoo Kim, G. Riccardi, P. Eugenio, A. Starostin, M. Taiuti, Michael Vineyard, and P. Collins

Subjects
Physics, 010308 nuclear & particles physics, Scattering, Nuclear Theory, General Physics and Astronomy, Scintillator, 7. Clean energy, 01 natural sciences, Nuclear physics, Dipole, Deuterium, 0103 physical sciences, Magnetic form factor, Neutron detection, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Electron scattering
Abstract

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

Published
2009

41. Search for the Photoexcitation of Exotic Mesons in theπ+π+π−System

Author

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

Subjects
Quantum chromodynamics, Physics, Particle physics, Meson, 010308 nuclear & particles physics, Partial wave analysis, Bremsstrahlung, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Nuclear physics, Excited state, 0103 physical sciences, Isobar, Production (computer science), 010306 general physics, Spin-½
Abstract

A search for exotic mesons in the $$\pi^{+}\pi^{+}\pi^{-}$$ system photoproduced by the charge exchange reaction $$\gamma p\to \pi^{+}\pi^{+}\pi^{-}(n)$$ was carried out by the CLAS collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A Partial Wave Analysis (PWA) was performed on a sample of 83,000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic $$J^{PC} = 1^{-+}$$ resonant state in the 1 to 2 GeV mass range. Our PWA analysis, based on the isobar model, shows production of the $$a_{2}(1320)$$ and the $$\pi_{2}(1670)$$ mesons, but no evidence for the $$a_{1}(1260)$$, nor the $$\pi_{1}(1600)$$ exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic $$\pi_1(1600)$$ cross section, less than 2% of the $a_2(1320)

Published
2009

42. Ratios ofN15/C12andHe4/C12inclusive electroproduction cross sections in the nucleon resonance region

Author

K. S. Egiyan, L. Guo, K. Mikhailov, Calarco, P. Stoler, K. Hicks, Susan Taylor, M. Ungaro, C. D. Keith, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, H. Egiyan, P. Corvisiero, C. E. Hyde-Wright, Y. Ilieva, R. A. Miskimen, G. Ricco, M. Amarian, E. Wolin, B. Zhao, B. McKinnon, R. Fatemi, S. Strauch, Laird Kramer, K. Park, B. B. Niczyporuk, P. Dragovitsch, Nikolay Shvedunov, J. P. Ball, Y. Prok, D. S. Carman, K. Joo, L. M. Qin, R. Suleiman, D. Branford, N. Pivnyuk, Shifeng Chen, A. V. Vlassov, Sergey Kuleshov, J. Yun, D. Cords, M. Mirazita, D. G. Crabb, J. M. Laget, M. Bektasoglu, G. S. Mutchler, S. Niccolai, A. Yegneswaran, M. Battaglieri, Niroula, A. Fradi, M. Nozar, N. A. Baltzell, J. Hardie, P. Eugenio, H. G. Juengst, S. A. Morrow, R. De Vita, O. Pogorelko, C. Djalali, Kubarovsky, C. Paterson, Friedrich Klein, K. A. Griffioen, R. J. Feuerbach, N. Markov, K. Livingston, M. Klusman, M. Taiuti, A.V. Stavinsky, N. Kalantarians, Brian Raue, F. W. Hersman, R. Bradford, K. Lukashin, Marco A. Huertas, D. J. Tedeschi, J. Langheinrich, A. I. Ostrovidov, A. C S Lima, J. T. Goetz, J. Shaw, E. Polli, S. S. Stepanyan, Crede, S. A. Philips, P. Collins, D. G. Ireland, Michael Wood, K. Hafidi, I. Bedlinskiy, Batourine, Elton Smith, Gerard Gilfoyle, Mestayer, Volker D. Burkert, V. S. Serov, L. C. Dennis, A. S. Biselli, N. Guler, B. E. Bonner, H. Avakian, B. Carnahan, G. Gavalian, S. Tkachenko, M. Anghinolfi, N. Benmouna, M. Ripani, Kwangsoo Kim, J. Kuhn, J. Zhang, S Anefalos, R. W. Gothe, G. Riccardi, A. Cazes, James Mueller, J. W C McNabb, Maryam Moteabbed, Bernhard Mecking, J. D. Kellie, S. Barrow, C. Butuceanu, K. V. Dharmawardane, E. Pasyuk, H. Bagdasaryan, Mokeev, Cynthia Marie Hadjidakis, E. De Sanctis, P. D. Rubin, K. Y. Kim, Y. G. Sharabian, M. Guidal, S. A. Dytman, R. G. Fersch, Michael Dugger, H. O. Funsten, L. Todor, N. Baillie, D. I. Sober, D. Protopopescu, M. Holtrop, S. Pozdniakov, M. Garçon, Hong Lu, Sbr Ultmann, Dinko Pocanic, Sylvain Bouchigny, P. L. Cole, P. Rossi, S. E. Kuhn, M. Bellis, J. Lachniet, H. Denizli, A. Tkabladze, D. Rowntree, Sapunenko, R. S. Hakobyan, A. V. Skabelin, P. Nadel-Turonski, Tsutomu Mibe, R. C. Minehart, C. A. Meyer, G. V. Fedotov, B. E. Stokes, G. S. Adams, D. P. Weygand, U. Thoma, M. Khandaker, L. C. Smith, B. S. Ishkhanov, D. Doughty, D. Heddle, Gyurjyan, W. Kim, S. Stepanyan, G. Niculescu, M. MacCormick, I. Hleiqawi, G. Rosner, R. Nasseripour, P. Bosted, S. L. Careccia, K. L. Giovanetti, Larry Weinstein, P. Coltharp, M. M. Ito, M. Osipenko, F. Sabatié, M. Guillo, K. Beard, L. Elouadrhiri, A. Deur, W. K. Brooks, R. A. Schumacher, G. V. O'Rielly, E. Golovatch, L. Morand, T. A. Forest, J. Pierce, Avraham Klein, Z. W. Zhao, J. P. Cummings, Hall Crannell, M. Kossov, D. G. Jenkins, G. E. Dodge, P. V. Degtyarenko, S. McAleer, F. X. Girod, I. Niculescu, D. Lawrence, J. W. Price, R. De Masi, Ji Li, E. L. Isupov, Michael L. Williams, S. Boiarinov, Michael Vineyard, B. M. Preedom, Lorenzo Zana, J. P. Santoro, H. S. Jo, and C. Salgado

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Hadron, Carbon-12, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Baryon, Helium-4, 0103 physical sciences, Phenomenological model, Atomic physics, 010306 general physics, Nucleon
Abstract

The (W,Q{sup 2}) dependence of the ratio of inclusive electron scattering cross sections for {sup 15}N/{sup 12}C was determined in the kinematic ranges 0.8

Published
2008

43. Polarized structure functionσLT'forH1(e→,e'K+)Λin the nucleon resonance region

Author

L. C. Dennis, B. E. Bonner, S. McAleer, F. X. Girod, L. Blaszczyk, H. Avakian, D. Sharov, D. Lawrence, P. Stoler, K. Hicks, K. S. Egiyan, Laird Kramer, D. Doughty, L. C. Smith, E. Munevar, V. Mokeev, K. Mikhailov, Elton Smith, J. Langheinrich, S. S. Stepanyan, S. A. Philips, W. J. Briscoe, E. Pasyuk, B. S. Ishkhanov, D. P. Watts, S. A. Dytman, R. A. Schumacher, P. Eugenio, D. Heddle, H. Egiyan, J. W. Price, M. F. Vineyard, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Nadel-Turonski, Tsutomu Mibe, H. G. Juengst, P. Corvisiero, E. Wolin, M. Taiuti, M. Anghinolfi, M. Kossov, James Mueller, E. De Sanctis, M. R. Niroula, J. P. Ball, M. Battaglieri, Y. Ilieva, P. D. Rubin, Y. G. Sharabian, A.V. Stavinsky, D. S. Carman, Patrick Girard, W. Kim, T. A. Forest, G. Niculescu, J. Lachniet, D. I. Sober, R. J. Feuerbach, Michael Wood, A. I. Ostrovidov, V. Sapunenko, L. Casey, Dinko Pocanic, R. Bradford, K. Lukashin, D. J. Tedeschi, K. Park, C. Hanretty, S. Stepanyan, K. Hafidi, D. G. Crabb, J. Pierce, V. S. Serov, S. E. Kuhn, Avraham Klein, E. Anciant, B. E. Stokes, B. B. Niczyporuk, I. Bedlinskiy, G. Ricco, D. G. Ireland, B. Moreno, G. E. Dodge, H. Y. Lu, P. V. Degtyarenko, N. Pivnyuk, Volker D. Burkert, A. S. Biselli, G. Audit, C. E. Hyde-Wright, R. Fatemi, A. V. Vlassov, R. De Vita, Z. W. Zhao, V. Kuznetsov, K. Joo, S. Procureur, Maryam Moteabbed, B. Zhao, D. G. Jenkins, Bernhard Mecking, Z. Krahn, Shifeng Chen, D. Sayre, S. Strauch, P. Collins, D. Protopopescu, I. Niculescu, M. Khandaker, S. Pozdniakov, Sylvain Bouchigny, J. J. Manak, P. Rossi, N. Baillie, S. Anefalos Pereira, A. Fradi, C. Cetina, A. Shafi, P. Dragovitsch, P. Mattione, Friedrich Klein, Kwangsoo Kim, R. A. Miskimen, B. McKinnon, V. P. Kubarovsky, G. Riccardi, J. Salamanca, Sergey Kuleshov, M. Osipenko, R. De Masi, Brian Raue, D. Branford, M. Mirazita, J. M. Laget, J. W C McNabb, S. A. Morrow, C. Djalali, G. S. Mutchler, M. Bektasoglu, S. Niccolai, F. Sabatié, N. Gevorgyan, C. Butuceanu, K. Beard, F. W. Hersman, N. A. Baltzell, J. T. Goetz, K. Livingston, D. S. Dale, N. Markov, O. Pogorelko, P. Coltharp, V. Crede, K. A. Griffioen, R. Dickson, J. Hardie, M. J. Amaryan, Kalvir S. Dhuga, P. Ambrozewicz, Gerard Gilfoyle, M. Nozar, D. Sokhan, M. MacCormick, M. Bellis, I. Hleiqawi, M. M. Ito, S. L. Careccia, J. Kuhn, R. W. Gothe, G. Gavalian, N. Guler, J. R. Calarco, G. A. Peterson, S. Simionatto, J. D. Kellie, S. Taylor, S. Tkachenko, K. Y. Kim, K. L. Giovanetti, B. Asavapibhop, J. P. Santoro, Roy Thompson, Larry Weinstein, S. Barrow, N. Benmouna, M. Ripani, M. Guidal, M. Guillo, L. Cheng, M. D. Mestayer, G. Rosner, R. Nasseripour, Nikolay Shvedunov, J. Hu, E. L. Isupov, L. Elouadrhiri, M. Holtrop, Michael L. Williams, S. Boiarinov, I. I. Strakovsky, B. M. Preedom, A. Deur, Lorenzo Zana, N. Kalantarians, H. Hakobyan, H. S. Jo, Gerald Feldman, Michael Dugger, W. K. Brooks, K. Wang, H. O. Funsten, C. Salgado, B. L. Berman, L. M. Qin, C. Paterson, Thierry Auger, M. Garçcon, J. R. Johnstone, V. Gyurjyan, J. Zhang, H. Bagdasaryan, L. Guo, M. Ungaro, A. Tkabladze, J. Yun, D. Cords, L. El Fassi, A. Yegneswaran, P. L. Cole, Y. Prok, Barry Ritchie, R. C. Minehart, Kei Moriya, C. A. Meyer, G. V. Fedotov, D. P. Weygand, A. V. Skabelin, and N. Dashyan

Subjects
Physics, Nuclear and High Energy Physics, Angular range, 010308 nuclear & particles physics, Hydrogen-1, Structure function, Hyperon, Sigma, Resonance, Lambda, 01 natural sciences, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The first measurements of the polarized structure function {sigma}{sub LT{sup '}} for the reaction {sup 1}H(e-vector,e{sup '}K{sup +}){lambda} in the nucleon resonance region are reported. Measurements are included from threshold up to W=2.05 GeV for central values of Q{sup 2} of 0.65 and 1.00 GeV{sup 2}, and nearly the entire kaon center-of-mass angular range. {sigma}{sub LT{sup '}} is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate s-channel resonances, as well as resonant and nonresonant processes. The results for {sigma}{sub LT{sup '}} are comparable in magnitude to previously reported results from CLAS for {sigma}{sub LT}, the real part of the same response. An intriguing sign change in {sigma}{sub LT{sup '}} is observed in the high Q{sup 2} data at W{approx_equal}1.9 GeV. Comparisons to several existing model predictions are shown.

Published
2008

44. Measurement ofep→epπ0beam spin asymmetries above the resonance region

Author

R. De Masi, M. Garçon, B. Zhao, M. J. Amaryan, P. Ambrozewicz, M. Anghinolfi, G. Asryan, H. Avakian, H. Bagdasaryan, N. Baillie, J. Ball, J. P. Ball, N. A. Baltzell, V. Batourine, M. Battaglieri, I. Bedlinskiy, M. Bellis, N. Benmouna, B. L. Berman, P. Bertin, A. S. Biselli, L. Blaszczyk, S. Bouchigny, S. Boiarinov, R. Bradford, D. Branford, W. J. Briscoe, W. K. Brooks, S. Bültmann, V. D. Burkert, C. Butuceanu, J. R. Calarco, S. L. Careccia, D. S. Carman, L. Casey, S. Chen, L. Cheng, P. L. Cole, P. Collins, P. Coltharp, D. Crabb, V. Crede, N. Dashyan, E. De Sanctis, R. De Vita, P. V. Degtyarenko, A. Deur, K. V. Dharmawardane, R. Dickson, C. Djalali, G. E. Dodge, J. Donnelly, D. Doughty, M. Dugger, O. P. Dzyubak, H. Egiyan, K. S. Egiyan, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, G. Feldman, A. Fradi, H. Funsten, G. Gavalian, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, J. T. Goetz, A. Gonenc, R. W. Gothe, K. A. Griffioen, M. Guidal, N. Guler, L. Guo, V. Gyurjyan, K. Hafidi, H. Hakobyan, C. Hanretty, F. W. Hersman, K. Hicks, I. Hleiqawi, M. Holtrop, C. E. Hyde-Wright, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, M. M. Ito, D. Jenkins, H. S. Jo, J. R. Johnstone, K. Joo, H. G. Juengst, N. Kalantarians, J. D. Kellie, M. Khandaker, W. Kim, A. Klein, F. J. Klein, A. V. Klimenko, M. Kossov, Z. Krahn, L. H. Kramer, V. Kubarovsky, J. Kuhn, S. E. Kuhn, S. V. Kuleshov, J. Lachniet, J. M. Laget, J. Langheinrich, D. Lawrence, T. Lee, K. Livingston, H. Y. Lu, M. MacCormick, N. Markov, P. Mattione, M. Mazouz, B. McKinnon, B. A. Mecking, M. D. Mestayer, C. A. Meyer, T. Mibe, B. Michel, K. Mikhailov, M. Mirazita, R. Miskimen, V. Mokeev, B. Moreno, K. Moriya, S. A. Morrow, M. Moteabbed, E. Munevar, G. S. Mutchler, P. Nadel-Turonski, R. Nasseripour, S. Niccolai, G. Niculescu, I. Niculescu, B. B. Niczyporuk, M. R. Niroula, R. A. Niyazov, M. Nozar, M. Osipenko, A. I. Ostrovidov, K. Park, E. Pasyuk, C. Paterson, S. Anefalos Pereira, J. Pierce, N. Pivnyuk, D. Pocanic, O. Pogorelko, S. Pozdniakov, J. W. Price, S. Procureur, Y. Prok, D. Protopopescu, B. A. Raue, G. Ricco, M. Ripani, B. G. Ritchie, F. Ronchetti, G. Rosner, P. Rossi, F. Sabatié, J. Salamanca, C. Salgado, J. P. Santoro, V. Sapunenko, R. A. Schumacher, V. S. Serov, Y. G. Sharabian, D. Sharov, N. V. Shvedunov, E. S. Smith, L. C. Smith, D. I. Sober, D. Sokhan, A. Stavinsky, S. Stepanyan, S. S. Stepanyan, B. E. Stokes, P. Stoler, I. I. Strakovsky, S. Strauch, M. Taiuti, D. J. Tedeschi, A. Tkabladze, S. Tkachenko, C. Tur, M. Ungaro, M. F. Vineyard, A. V. Vlassov, E. Voutier, D. P. Watts, L. B. Weinstein, D. P. Weygand, M. Williams, E. Wolin, M. H. Wood, A. Yegneswaran, L. Zana, J. Zhang, and Z. W. Zhao

Subjects
Physics, Nuclear and High Energy Physics, Photon, Spectrometer, 010308 nuclear & particles physics, media_common.quotation_subject, Parton, 01 natural sciences, Asymmetry, Nuclear physics, Formalism (philosophy of mathematics), Amplitude, 0103 physical sciences, Cathode ray, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, media_common
Abstract

The beam spin asymmetry (BSA) in the exclusive reaction ep->ep pi0 was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer(CLAS). The xB, Q2, t and phi dependences of the pi0 BSA are presented in the deep inelastic regime. The asymmetries are fitted with a sin(phi) function and their amplitudes are extracted. Overall, they are of the order of 0.04 - 0.11 and roughly independent of t. This is the signature of a non-zero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.

Published
2008

45. Cross sections and beam asymmetries fore→p→enπ+in the nucleon resonance region for1.7⩽Q2⩽4.5GeV2

Author

R. Fatemi, A. V. Vlassov, T. Lee, H. G. Juengst, A. Fradi, R. De Vita, A.V. Stavinsky, N. Markov, N. Hassall, B. Zhao, D. J. Tedeschi, S. Park, Sylvain Bouchigny, K. Hafnaoui, K. Livingston, D. S. Dale, G. Rosner, R. Nasseripour, I. Bedlinskiy, S. Anefalos Pereira, P. Rossi, E. Wolin, R. Dickson, Ji Li, J. P. Ball, Y. Prok, F. W. Hersman, V. Kuznetsov, J. P. Cummings, V. Sapunenko, Dinko Pocanic, C. Hanretty, N. Guler, S. McAleer, F. X. Girod, L. Blaszczyk, D. G. Ireland, V. Crede, S. E. Kuhn, M. Osipenko, F. Sabatié, J. Lachniet, H. Denizli, A. Tkabladze, J. R. Johnstone, M. Kossov, J. R. Calarco, D. G. Crabb, D. Rowntree, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, A. I. Ostrovidov, A. C S Lima, R. Suleiman, I. Popa, G. S. Mutchler, L. Guo, G. E. Dodge, H. Y. Lu, M. Ungaro, D. Doughty, M. D. Mestayer, S. Niccolai, E. De Sanctis, Volker D. Burkert, A. S. Biselli, E. L. Isupov, C. Tur, M. Guillo, D. Heddle, W. Gohn, M. Guidal, J. Hardie, Z. Krahn, J. Kuhn, P. L. Cole, S. Barrow, Elton Smith, Friedrich Klein, M. Yurov, Kalvir S. Dhuga, Michael L. Williams, P. V. Degtyarenko, N. Baillie, M. Anghinolfi, James Mueller, A. V. Skabelin, L. Todor, D. Protopopescu, S. Mehrabyan, D. I. Sober, S. Pozdniakov, M. Garçon, J. Yun, D. Cords, S. S. Stepanyan, S. Boiarinov, P. D. Rubin, Y. G. Sharabian, A. Yegneswaran, R. A. Miskimen, Brian Raue, B. McKinnon, Atilla Gonenc, R. C. Minehart, Kei Moriya, C. A. Meyer, J. W. Price, T. Takeuchi, M. Holtrop, I. Niculescu, C. Bookwalter, G. V. Fedotov, W. Kim, G. Niculescu, G. Gavalian, Laird Kramer, G. Riccardi, D. Lawrence, Baile Zhang, Shifeng Chen, S. Dhamija, J. Shaw, P. Corvisiero, S. Tkachenko, L. El Fassi, D. Branford, Michael Wood, R. De Masi, B. E. Stokes, K. Hafidi, C. Butuceanu, D. Keller, D. Schott, G. S. Adams, N. A. Baltzell, V. Gyurjyan, N. Benmouna, M. Ripani, K. Joo, N. Dashyan, P. Mattione, D. P. Weygand, M. S. Saini, M. Mirazita, J. M. Laget, V. S. Serov, R. W. Gothe, Y. Ilieva, N. Gevorgyan, Michael Vineyard, J. Zhang, P. Nadel-Turonski, Alexei V. Klimenko, L. Cheng, Tsutomu Mibe, B. M. Preedom, L. Elouadrhiri, J. Langheinrich, K. Y. Kim, Nikolay Shvedunov, J. T. Goetz, E. Polli, H. Bagdasaryan, Lorenzo Zana, J. P. Santoro, Barry Ritchie, S. A. Philips, M. Khandaker, P. Eugenio, M. Taiuti, G. V. O'Rielly, Z. W. Zhao, I. I. Strakovsky, P. Stoler, J. D. Kellie, S. A. Morrow, V. P. Kubarovsky, V. Mokeev, R. A. Schumacher, B. Moreno, Gerard Gilfoyle, G. Ricco, C. Djalali, H. Hakobyan, H. S. Jo, Gerald Feldman, K. Hicks, O. Pogorelko, A. Deur, D. G. Jenkins, Federico Ronchetti, L. C. Dennis, L. Graham, P. Collins, B. E. Bonner, J. J. Melone, C. Salgado, D. Sokhan, K. Park, Daniel S. Carman, M. J. Amaryan, K. S. Egiyan, C. I O Gordon, N. Kalantarians, H. Avakian, W. K. Brooks, M. MacCormick, I. Hleiqawi, C. E. Hyde-Wright, D. Sharov, P. Ambrozewicz, K. Mikhailov, S. Bültmann, L. Morand, T. A. Forest, Cynthia Marie Hadjidakis, S. L. Careccia, Sergey Kuleshov, S. Stepanyan, K. L. Giovanetti, J. Pierce, Avraham Klein, Larry Weinstein, M. Bektasoglu, M. Nozar, Michael Dugger, H. O. Funsten, W. J. Briscoe, E. Pasyuk, S. A. Dytman, J. Salamanca, J. W C McNabb, L. Casey, B. B. Niczyporuk, N. Pivnyuk, V. Batourine, M. Battaglieri, L. C. Smith, E. Munevar, B. S. Ishkhanov, B. L. Berman, R. Bradford, B. A. Mecking, K. Lukashin, L. M. Qin, R. S. Hakobyan, K. A. Griffioen, C. Paterson, M. Klusman, D. P. Watts, M. R. Niroula, E. Golovatch, M. Bellis, S. Strauch, H. Egiyan, A. Cazes, Maryam Moteabbed, P. Coltharp, K. V. Dharmawardane, M. Y. Gabrielyan, R. J. Feuerbach, M. M. Ito, and Inna Aznauryan

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Resonance, 01 natural sciences, Excited state, Isospin, 0103 physical sciences, Production (computer science), Invariant mass, Sensitivity (control systems), Atomic physics, 010306 general physics, Nucleon
Abstract

The exclusive electroproduction process $\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}{e}^{'}n{\ensuremath{\pi}}^{+}$ was measured in the range of the photon virtuality ${Q}^{2}=1.7\text{\ensuremath{-}}4.5 {\mathrm{GeV}}^{2}$, and the invariant mass range for the $n{\ensuremath{\pi}}^{+}$ system of $W=1.15\text{\ensuremath{-}}1.7 \mathrm{GeV}$ using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive ${\ensuremath{\pi}}^{+}$ production from protons with nearly full coverage in the azimuthal and polar angles of the $n{\ensuremath{\pi}}^{+}$ center-of-mass system. The $n{\ensuremath{\pi}}^{+}$ channel has particular sensitivity to the isospin \textonehalf{} excited nucleon states, and together with the $p{\ensuremath{\pi}}^{0}$ final state will serve to determine the transition form factors of a large number of resonances. The largest discrepancy between these results and present modes was seen in the ${\ensuremath{\sigma}}_{{\mathit{LT}}^{'}}$ structure function. In this experiment, 31,295 cross section and 4,184 asymmetry data points were measured. Because of the large volume of data, only a reduced set of structure functions and Legendre polynomial moments can be presented that are obtained in model-independent fits to the differential cross sections.

Published
2008

46. Search for Medium Modifications of theρMeson

Author

S. A. Morrow, C. Djalali, C. Hanretty, A.V. Stavinsky, P. Ambrozewicz, D. J. Tedeschi, Baile Zhang, M. J. Amaryan, H. Juengst, R. A. Miskimen, B. McKinnon, M. MacCormick, Shifeng Chen, I. Bedlinskiy, Carlos A. Salgado, I. Hleiqawi, Andreas Klein, Ji Li, S. L. Careccia, D. Branford, L. Casey, B. B. Niczyporuk, N. Pivnyuk, Nikolay Shvedunov, M. Mirazita, J. M. Laget, K. L. Giovanetti, P. Collins, E. L. Isupov, N. Markov, J. Salamanca, Mark Richard James Williams, J. W C McNabb, Larry Weinstein, J. T. Goetz, S. Boiarinov, K. A. Griffioen, B. M. Preedom, S. McAleer, C. E. Hyde-Wright, J. P. Cummings, S. Niccolai, L. Elouadrhiri, S. Mehrabyan, H. Denizli, F. X. Girod, L. Blaszczyk, R. J. Feuerbach, Lorenzo Zana, J. Hardie, E. De Sanctis, Jens H. Kuhn, I. I. Strakovsky, A. I. Ostrovidov, K. Park, R. A. Schumacher, N. A. Baltzell, M. Khandaker, Dinko Pocanic, D. G. Ireland, V. Crede, Sergey Kuleshov, J. P. Santoro, M. Bektasoglu, H. Hakobyan, Federico Ronchetti, H. S. Jo, G. Riccardi, P. Muehlich, A. Deur, M. Kossov, Gerald Feldman, Volker D. Burkert, A. S. Biselli, S. E. Kuhn, J. R. Calarco, M. Guidal, Z. Krahn, L. C. Smith, E. Munevar, G. Ricco, D. I. Sober, S. Strauch, Rakhsha Nasseripour, K. Moriya, L. Todor, D. Doughty, C. Butuceanu, D. Protopopescu, N. Dashyan, G. Niculescu, M. Holtrop, N. Baillie, Mestayer, M. Battaglieri, B. S. Ishkhanov, S. Pozdniakov, M. Garçon, P. Eugenio, D. P. Watts, H. Egiyan, M. Taiuti, J. D. Kellie, R. C. Minehart, C. A. Meyer, B. Carnahan, S. Tkachenko, C. I O Gordon, F. Sabatié, V. Sapunenko, Laird Kramer, R. Bradford, B. A. Mecking, A. V. Vlassov, J. Langheinrich, G. V. Fedotov, N. Kalantarians, N. Benmouna, M. Ripani, M. Nozar, Yordanka Ilieva, Michael Vineyard, R. De Vita, Gerard Gilfoyle, M. Anghinolfi, Ulrich Mosel, J. J. Melone, Brian Raue, K. Livingston, James Mueller, D. P. Weygand, D. Sokhan, Cynthia Marie Hadjidakis, E. S. Smith, Maryam Moteabbed, M. R. Niroula, Alexei V. Klimenko, S. Anefalos Pereira, D. G. Jenkins, G. S. Mutchler, Michael Dugger, H. O. Funsten, Y. G. Sharabian, K. V. Dharmawardane, E. Wolin, B. L. Berman, S. Stepanyan, L. C. Dennis, R. Dickson, Sylvain Bouchigny, Barry Ritchie, J. P. Ball, Y. Prok, D. S. Carman, P. Rossi, C. Paterson, D. G. Crabb, J. Pierce, H. Avakian, P. Mattione, D. Sharov, N. Guler, G. E. Dodge, H. Y. Lu, P. V. Degtyarenko, S. Barrow, I. Niculescu, D. Lawrence, R. De Masi, P. Coltharp, William Brooks, Hall Crannell, M. M. Ito, S. Bültmann, W. J. Briscoe, E. Pasyuk, J. R. Johnstone, L. Guo, M. Ungaro, S. A. Dytman, M. Bellis, K. Joo, S. S. Stepanyan, A. Yegneswaran, V. Gyurjyan, J. Zhang, H. Bagdasaryan, J. W. Price, V. P. Kubarovsky, G. Rosner, O. Pogorelko, Frank Klein, Michael Wood, K. Hafidi, K. S. Egiyan, V. S. Serov, B. E. Stokes, G. S. Adams, K. Mikhailov, Clarisse Tur, P. Nadel-Turonski, Tsutomu Mibe, G. Gavalian, V. Mokeev, P. Stoler, W. Kim, J. Lachniet, K. Hicks, A. Tkabladze, R. S. Hakobyan, L. El Fassi, M. Osipenko, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. L. Cole, Z. W. Zhao, B. Zhao, F. W. Hersman, and R. W. Gothe

Subjects
Physics, Particle physics, Rho meson, Meson, Spectrometer, Nuclear Theory, Spectrum (functional analysis), General Physics and Astronomy, Order (ring theory), Physics and Astronomy(all), Resonance (particle physics), medicine.anatomical_structure, Deuterium, medicine, High Energy Physics::Experiment, Nuclear Experiment, Nucleus
Abstract

The photoproduction of vector mesons on various nuclei has been studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. The vector mesons, $$\rho$$, $$\omega$$, and $$\phi$$, are observed via their decay to $e^+e^-$, in order to reduce the effects of final state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the $$\rho$$ meson. The $$\rho$$ spectral function is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no significant mass shift for the $$\rho$$ meson; however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.

Published
2007

47. Erratum: Cross sections for theγp→K*0Σ+reaction atEγ=1.7−3.0GeV [Phys. Rev. C75, 042201 (2007)]

Author

Shifeng Chen, L. C. Dennis, M. Osipenko, H. Avakian, K. Livingston, K. Beard, K. A. Griffioen, J. Donnelly, G. Asryan, M. Battaglieri, R. Bradford, B. A. Mecking, O. P. Dzyubak, R. A. Niyazov, H. Egiyan, J. T. Goetz, R. Dickson, D. Doughty, G. Rosner, Carlos A. Salgado, J. W C McNabb, D. Heddle, A.V. Stavinsky, A. V. Vlassov, Maryam Moteabbed, W. J. Briscoe, E. Pasyuk, K. S. Egiyan, E. S. Smith, D. G. Jenkins, W. Kim, Laird Kramer, D. J. Tedeschi, Kwangsoo Kim, J. Lachniet, A. Tkabladze, S. A. Dytman, S. E. Kuhn, B. B. Niczyporuk, G. Riccardi, K. Mikhailov, B. L. Berman, M. Amarian, N. Guler, R. De Vita, I. Bedlinskiy, Andreas Klein, J. Langheinrich, B. E. Stokes, V. Sapunenko, C. Butuceanu, Sylvain Bouchigny, N. Pivnyuk, E. Wolin, Stephen Taylor, K. Lukashin, Ji Li, U. Thoma, C. Paterson, M. Bellis, P. Rossi, Gerard Gilfoyle, S. McAleer, F. X. Girod, S. A. Morrow, G. Gavalian, P. Stoler, R. S. Hakobyan, V. Batourine, S. Niccolai, C. Djalali, J. P. Ball, D. G. Ireland, M. D. Mestayer, V. Crede, G. Ricco, Y. Prok, V. Mokeev, D. S. Carman, J. Hardie, M. MacCormick, B. Carnahan, F. Sabatié, K. Hicks, J. R. Calarco, P. Ambrozewicz, Michael L. Williams, I. Hleiqawi, S. L. Careccia, V. P. Kubarovsky, S. Strauch, Atilla Gonenc, H. Juengst, D. G. Crabb, J. P. Cummings, G. S. Mutchler, M. Guidal, Z. Krahn, L. C. Smith, E. Munevar, N. A. Baltzell, E. De Sanctis, O. Pogorelko, K. L. Giovanetti, G. Niculescu, R. W. Gothe, N. Baillie, R. A. Miskimen, B. McKinnon, M. Anghinolfi, Larry Weinstein, B. S. Ishkhanov, S. Boiarinov, D. I. Sober, D. Branford, L. Elouadrhiri, M. R. Niroula, Yordanka Ilieva, M. Mirazita, J. M. Laget, M. Kossov, Frank Klein, I. I. Strakovsky, J. D. Kellie, A. Deur, R. G. Fersch, Rakhsha Nasseripour, M. Holtrop, Michael Dugger, B. Zhao, M. Khandaker, Brian Raue, P. Coltharp, Y. G. Sharabian, M. M. Ito, A. I. Ostrovidov, Michael Wood, K. Park, Michael Vineyard, Hong Lu, P. L. Cole, Z. W. Zhao, F. W. Hersman, S. Whisnant, B. M. Preedom, V. S. Serov, Federico Ronchetti, Lorenzo Zana, Volker D. Burkert, A. S. Biselli, Clarisse Tur, P. Nadel-Turonski, H. S. Jo, Tsutomu Mibe, Gerald Feldman, C. E. Hyde-Wright, R. C. Minehart, K. Wang, C. A. Meyer, K. Moriya, R. J. Feuerbach, Jens H. Kuhn, Sergey Kuleshov, S. Tkachenko, N. Benmouna, V. Gyurjyan, M. Ripani, G. V. Fedotov, N. Kalantarians, L. Todor, J. Zhang, H. Bagdasaryan, D. Protopopescu, J. W. Price, L. Guo, S. Pozdniakov, M. Garçon, M. Ungaro, K. Joo, S. S. Stepanyan, A. Yegneswaran, D. P. Weygand, Alexei V. Klimenko, Barry Ritchie, G. E. Dodge, P. V. Degtyarenko, I. Niculescu, D. Lawrence, R. De Masi, R. A. Schumacher, M. Nozar, S. Bültmann, S. Stepanyan, J. Pierce, William Brooks, Hall Crannell, P. Eugenio, M. Taiuti, P. Collins, J. P. Santoro, and Roy Thompson

Subjects
Baryon, Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Hadron, Elementary particle, Fermion, Boson, Sigma baryon
Published
2007

48. π0photoproduction on the proton for photon energies from 0.675 to 2.875 GeV

Author

B. M. Preedom, J. P. Ball, D. S. Carman, L. C. Dennis, B. E. Bonner, R. A. Schumacher, H. Avakian, J. Kuhn, J. P. Santoro, Roy Thompson, B. Carnahan, D. G. Crabb, P. Eugenio, M. Taiuti, P. Collins, R. A. Niyazov, F. Sabatié, S. Bültmann, T. A. Forest, A. I. Ostrovidov, J. Langheinrich, A. C S Lima, W. J. Briscoe, V. Gyurjyan, S. S. Stepanyan, P. Stoler, J. Slamanca, S. A. Philips, S. Stepanyan, H. S. Jo, Gerald Feldman, E. Pasyuk, Valeria Muccifora, J. Pierce, Avraham Klein, D. Doughty, S. A. Dytman, D. G. Ireland, K. Wang, K. Hicks, J. Zhang, H. Bagdasaryan, D. Heddle, L. Elouadrhiri, R. J. Feuerbach, I. I. Strakovsky, Volker D. Burkert, B. B. Niczyporuk, A. S. Biselli, Gerard Gilfoyle, Marco A. Huertas, H. G. Juengst, L. Zana, G. E. Dodge, P. Coltharp, A. Deur, B. E. Stokes, W. K. Brooks, N. Pivnyuk, P. V. Degtyarenko, G. S. Adams, W. Kim, G. Gavalian, A.V. Stavinsky, J. Shaw, G. Niculescu, J. Napolitano, B. L. Berman, J. Donnelly, G. Asryan, O. P. Dzyubak, S. Tkachenko, Federico Ronchetti, Kwangsoo Kim, G. Riccardi, R. Fatemi, C. Butuceanu, Laird Kramer, M. M. Ito, L. M. Qin, F. W. Hersman, M. Kossov, A. V. Vlassov, Sylvain Bouchigny, P. Rossi, E. Anciant, G. V. O'Rielly, M. D. Mestayer, K. Joo, I. Niculescu, D. Lawrence, N. Benmouna, P. Corvisiero, M. Ripani, Carlos A. Salgado, G. Ricco, Michael L. Williams, Victor Mokeev, T. Lee, D. J. Tedeschi, M. Amarian, L. Guo, P. Nadel-Turonski, Tsutomu Mibe, Z. Krahn, Y. Ilieva, M. Spraker, M. Ungaro, Michael Wood, V. S. Serov, M. Guidal, Susan Taylor, S. Strauch, M. Khandaker, N. Baillie, C. Paterson, M. Klusman, S. Boiarinov, J. P. Cummings, R. De Vita, R. A. Miskimen, K. Park, K. S. Egiyan, B. McKinnon, D. G. Jenkins, H. Egiyan, L. C. Maximon, K. Mikhailov, A. Coleman, I. Hleiqawi, H. R. Weller, J. R. Calarco, M. Guillo, I. Bedlinskiy, S. L. Careccia, S. Simionatto, M. Holtrop, S. McAleer, Friedrich Klein, D. Branford, F. X. Girod, Brian Raue, N. Kalantarians, Hall Crannell, J. J. Manak, M. Osipenko, M. Mirazita, K. L. Giovanetti, B. Asavapibhop, Cynthia Marie Hadjidakis, J. M. Laget, A. Tkabladze, J. Yun, D. Cords, Larry Weinstein, J. W C McNabb, D. Rowntree, K. Beard, L. C. Smith, A. Yegneswaran, Michael Dugger, H. O. Funsten, Michael Vineyard, V. P. Kubarovsky, Nicola Bianchi, R. W. Gothe, B. S. Ishkhanov, Kalvir S. Dhuga, C. Marchand, V. Kuznetsov, S. A. Morrow, C. Djalali, L. Todor, A. Empl, R. S. Hakobyan, O. Pogorelko, K. Y. Kim, G. Rosner, R. Nasseripour, E. De Sanctis, D. Protopopescu, J. W. Price, M. R. Niroula, S. Pozdniakov, M. Garçon, G. Audit, C. E. Hyde-Wright, J. Lachniet, D. I. Sober, A. Shafi, P. Ambrozewicz, P. Dragovitsch, M. Bektasoglu, M. Nozar, K. Livingston, S. Niccolai, P. L. Cole, R. Dickson, J. Hardie, N. Guler, S. Barrow, M. Battaglieri, N. A. Baltzell, K. A. Griffioen, J. D. Kellie, Ron L. Workman, R. Bradford, K. Lukashin, G. S. Mutchler, M. Bellis, J. Hu, Alexei V. Klimenko, R. A. Arndt, Barry Ritchie, Bernhard Mecking, K. V. Dharmawardane, R. C. Minehart, Kei Moriya, C. A. Meyer, G. V. Fedotov, Y. Prok, D. P. Weygand, H. Denizli, A. V. Skabelin, Shifeng Chen, J. T. Goetz, V. Sapunenko, Dinko Pocanic, S. E. Kuhn, C. Tur, Elton Smith, J. R. Ficenec, M. Anghinolfi, James Mueller, P. D. Rubin, Y. G. Sharabian, and E. Wolin

Subjects
Physics, Normalization (statistics), Nuclear and High Energy Physics, Particle physics, Photon, Spectrometer, Proton, 010308 nuclear & particles physics, Forward scatter, Scattering, 01 natural sciences, Particle identification, Nuclear physics, 0103 physical sciences, Photon beam, Nuclear Experiment, 010306 general physics
Abstract

Differential cross sections for the reaction $\gamma p \to p \pi^0$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.675 to 2.875 GeV. The results reported here possess greater accuracy in the absolute normalization than previous measurements. They disagree with recent CB-ELSA measurements for the process at forward scattering angles. Agreement with the SAID and MAID fits is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been extended to 3 GeV. Resonance couplings have been extracted and compared to previous determinations.

Published
2007

49. Q2dependence of theS11(1535)photocoupling and evidence for aP-wave resonance in η electroproduction

Author

S. A. Morrow, Laird Kramer, P. Dragovitsch, P. Stoler, Barry Ritchie, J. Hardie, S. O. Nelson, K. Hicks, H. G. Juengst, M. L. Leber, Federico Ronchetti, K. Livingston, A.V. Stavinsky, D. J. Tedeschi, J. Kuhn, N. A. Baltzell, R. C. Minehart, C. A. Meyer, G. V. Fedotov, R. Dickson, L. Elouadrhiri, H. Denizli, J. P. Santoro, Roy Thompson, D. P. Weygand, I. Bedlinskiy, K. A. Griffioen, G. Ricco, N. Markov, J. Langheinrich, S. S. Stepanyan, N. Dashyan, S. A. Philips, I. I. Strakovsky, N. Guler, M. Bellis, G. A. Peterson, K. S. Egiyan, Nikolay Shvedunov, A. Deur, V. Frolov, M. J. Amaryan, K. Mikhailov, Shifeng Chen, R. J. Feuerbach, A. I. Ostrovidov, P. Eugenio, R. Fatemi, B. B. Niczyporuk, S. Barrow, W. K. Brooks, M. Taiuti, V. Batourine, I. Hleiqawi, Friedrich Klein, Y. Ilieva, C. Cetina, A. V. Vlassov, S. L. Careccia, N. Kalantarians, J. Hu, J. D. Kellie, J. P. Cummings, S. Simionatto, C. E. Hyde-Wright, Brian Raue, N. Pivnyuk, J. Napolitano, Michael Vineyard, L. Farhi, D. Rowntree, Sergey Kuleshov, N. Baillie, J. T. Goetz, E. Polli, M. Bektasoglu, M. Nozar, V. Gyurjyan, G. V. O'Rielly, P. Collins, Maryam Moteabbed, K. L. Giovanetti, B. Asavapibhop, M. Kossov, M. MacCormick, Valeria Muccifora, Bernhard Mecking, V. Sapunenko, Dinko Pocanic, R. De Vita, J. Zhang, M. Guidal, Z. W. Zhao, G. Gavalian, S. Tkachenko, R. A. Schumacher, Susan Taylor, N. Benmouna, P. L. Cole, M. Spraker, Larry Weinstein, D. Doughty, G. Rosner, L. C. Smith, S. J. Gaff, H. Bagdasaryan, R. Nasseripour, M. Holtrop, D. G. Jenkins, C. Djalali, M. D. Mestayer, E. L. Isupov, M. Ripani, L. Guo, S. Strauch, Gerard Gilfoyle, K. Sabourov, D. Heddle, Nicola Bianchi, D. P. Watts, H. Egiyan, S. Bültmann, M. Ungaro, Michael L. Williams, B. S. Ishkhanov, Sylvain Bouchigny, S. E. Kuhn, T. A. Forest, D. Sokhan, S. Stepanyan, P. Nadel-Turonski, B. E. Stokes, J. W. Price, J. Pierce, Avraham Klein, G. S. Adams, Tsutomu Mibe, G. E. Dodge, J. J. Manak, S. Boiarinov, Michael Dugger, S. McAleer, B. M. Preedom, H. Y. Lu, P. Rossi, H. O. Funsten, F. X. Girod, P. V. Degtyarenko, D. Protopopescu, R. A. Miskimen, B. McKinnon, J. H. Kelley, K. Joo, G. S. Mutchler, S. Pozdniakov, M. Garçon, L. M. Qin, J. Yun, D. Cords, C. Tur, Lorenzo Zana, D. G. Ireland, A. Shafi, A. Yegneswaran, I. Niculescu, M. Battaglieri, V. Crede, D. Lawrence, D. Branford, P. Ambrozewicz, H. Hakobyan, Kwangsoo Kim, G. Riccardi, Gerald Feldman, K. Moriya, U. Thoma, J. R. Calarco, A. Tkabladze, M. Mirazita, J. M. Laget, C. Paterson, Elton Smith, K. Wang, C. Salgado, Atilla Gonenc, M. R. Niroula, M. Klusman, R. Bradford, K. Lukashin, C. Butuceanu, M. Guillo, E. De Sanctis, M. Khandaker, M. Anghinolfi, E. Wolin, H. S. Jo, R. S. Hakobyan, James Mueller, L. El Fassi, P. D. Rubin, J. P. Ball, Y. Prok, Y. G. Sharabian, D. S. Carman, J. Lachniet, D. I. Sober, S. Niccolai, D. G. Crabb, J. Salamanca, J. W C McNabb, A. Coleman, H. R. Weller, Volker D. Burkert, A. S. Biselli, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, P. Corvisiero, J. Miles, P. Coltharp, M. Osipenko, F. Sabatié, M. M. Ito, K. Beard, R. W. Gothe, Kalvir S. Dhuga, K. Y. Kim, W. Kim, A. V. Skabelin, G. Niculescu, B. Zhao, R. D. Levine, V. Mokeev, F. W. Hersman, L. C. Dennis, B. E. Bonner, H. Avakian, W. J. Briscoe, E. Pasyuk, S. A. Dytman, Patrick Girard, J. Shaw, Michael Wood, K. Hafidi, V. S. Serov, K. Park, V. P. Kubarovsky, A. Empl, and O. Pogorelko

Subjects
Baryon, Scattering cross-section, Physics, Nuclear and High Energy Physics, Cross section.transverse, Particle physics, Amplitude, Photon, Angular distribution, Momentum transfer, Resonance, High Energy Physics::Experiment
Abstract

New cross sections for the reaction $\mathit{ep}\ensuremath{\rightarrow}{e}^{'}\ensuremath{\eta}p$ are reported for total center-of-mass energy $W=1.5\text{\ensuremath{-}}2.3$ GeV and invariant squared momentum transfer ${Q}^{2}=0.13\text{\ensuremath{-}}3.3$ GeV${}^{2}$. This large kinematic range allows the extraction of new information about response functions, photocouplings, and $\ensuremath{\eta}N$ coupling strengths of baryon resonances. A sharp structure is seen at $W~1.7$ GeV. The shape of the differential cross section is indicative of the presence of a $P$-wave resonance that persists to high ${Q}^{2}$. Improved values are derived for the photocoupling amplitude for the ${S}_{11}$(1535) resonance. The new data greatly expand the ${Q}^{2}$ range covered, and an interpretation of all data with a consistent parametrization is provided.

Published
2007

50. First measurement of beam-recoil observablesCxandCzin hyperon photoproduction

Author

V. Gyurjyan, L. C. Dennis, B. E. Bonner, H. Avakian, Maryam Moteabbed, Bernhard Mecking, J. Zhang, K. V. Dharmawardane, H. Bagdasaryan, K. Park, F. Sabatiã, V. P. Kubarovsky, A. Empl, O. Pogorelko, S. A. Morrow, K. Lukashin, W. J. Briscoe, E. Pasyuk, L. C. Smith, V. Sapunenko, Dinko Pocanic, S. A. Dytman, B. S. Ishkhanov, Barry Ritchie, J. Kuhn, Hall Crannell, Marco Ripani, S. E. Kuhn, E. Anciant, Roy Thompson, C. Marchand, M. Bellis, J. Shaw, M. R. Niroula, Michael Wood, J. P. Cummings, K. Hafidi, V. S. Serov, L. Elouadrhiri, C. Tur, B. P. Quinn, R. A. Schumacher, G. V. O'Rielly, R. Fatemi, B. Zhao, Kei Moriya, Federico Ronchetti, C. A. Meyer, Victor Mokeev, Z. W. Zhao, J. Hu, M. Khandaker, G. V. Fedotov, M. Kossov, L. Guo, M. Ungaro, B. L. Berman, D. G. Jenkins, Cynthia Marie Hadjidakis, S. Bültmann, T. A. Forest, A. V. Vlassov, I. Popa, I. I. Strakovsky, J. Langheinrich, S. S. Stepanyan, S. A. Philips, A. Coleman, S. Stepanyan, P. Eugenio, B. B. Niczyporuk, H. R. Weller, N. Baillie, M. Battaglieri, R. A. Miskimen, B. McKinnon, P. Dragovitsch, D. P. Weygand, M. Taiuti, J. Pierce, Avraham Klein, Shifeng Chen, Michael Dugger, Kwangsoo Kim, G. Riccardi, N. Pivnyuk, L. M. Qin, J. Napolitano, H. O. Funsten, R. Bradford, J. Yun, D. Cords, Friedrich Klein, M. Osipenko, F. W. Hersman, G. E. Dodge, S. McAleer, F. X. Girod, A. Yegneswaran, C. Butuceanu, R. J. Feuerbach, A. Deur, H. Denizli, Brian Raue, D. Branford, P. V. Degtyarenko, R. De Vita, N. Guler, P. Collins, Marco A. Huertas, M. Mirazita, J. M. Laget, P. L. Cole, M. Guidal, W. K. Brooks, K. Beard, J. Hardie, G. Niculescu, A. V. Skabelin, I. Niculescu, Giovanni Ricco, Atilla Gonenc, M. D. Mestayer, J. J. Manak, H. G. Juengst, P. Coltharp, D. Lawrence, M. Holtrop, J. W. Price, C. Paterson, R. De Masi, E. L. Isupov, P. Nadel-Turonski, M. M. Ito, C. Djalali, R. W. Gothe, Tsutomu Mibe, A.V. Stavinsky, M. Klusman, Michael L. Williams, E. De Sanctis, M. MacCormick, J. T. Goetz, J. Lachniet, D. I. Sober, G. Audit, C. E. Hyde-Wright, E. Polli, M. Guillo, J. D. Kellie, Valeria Muccifora, D. J. Tedeschi, K. Y. Kim, G. Gavalian, S. Tkachenko, V. Batourine, S. Boiarinov, B. M. Preedom, H. Y. Lu, Sergey Kuleshov, I. Bedlinskiy, M. Bektasoglu, N. Benmouna, M. Nozar, Gerard Gilfoyle, E. Wolin, B. Carnahan, Elton Smith, P. Ambrozewicz, D. Sokhan, A. Tkabladze, Nikolay Shvedunov, D. Rowntree, Lorenzo Zana, J. P. Santoro, W. Kim, J. P. Ball, Y. Prok, U. Thoma, R. S. Hakobyan, M. Anghinolfi, D. S. Carman, Sylvain Bouchigny, L. El Fassi, N. Natasha, N. Kalantarians, James Mueller, S. Niccolai, D. G. Crabb, J. Salamanca, Susan Taylor, P. Rossi, J. W C McNabb, D. P. Watts, H. Egiyan, P. D. Rubin, Y. G. Sharabian, V. Crede, J. R. Calarco, B. E. Stokes, G. S. Adams, H. S. Jo, K. Joo, N. A. Baltzell, K. A. Griffioen, N. Markov, Laird Kramer, Y. Ilieva, S. Strauch, G. S. Mutchler, A. I. Ostrovidov, A. C S Lima, D. G. Ireland, Volker D. Burkert, A. S. Biselli, Nicola Bianchi, L. Todor, D. Protopopescu, S. Pozdniakov, M. Garçon, G. Rosner, R. Nasseripour, A. Shafi, K. S. Egiyan, K. Livingston, R. Dickson, K. Mikhailov, S. Barrow, P. Stoler, K. Hicks, J. Donnelly, G. Asryan, O. P. Dzyubak, R. A. Niyazov, M. J. Amaryan, I. Hleiqawi, S. L. Careccia, S. Simionatto, P. Corvisiero, K. L. Giovanetti, B. Asavapibhop, M. Spraker, Larry Weinstein, D. Doughty, D. Heddle, H. Hakobyan, Gerald Feldman, K. Wang, C. Salgado, and Michael Vineyard

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, Bremsstrahlung, Hyperon, Observable, Lambda, Polarization (waves), 01 natural sciences, Induced polarization, Nuclear physics, Recoil, 0103 physical sciences, Nuclear Experiment, 010306 general physics
Abstract

Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $$\vec\gamma + p \to K^+ + \vec\Lambda$$ and $$\vec\gamma + p \to K^+ + \vec\Sigma^0$$. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies $W$ between 1.6 and 2.53 GeV, and for $$-0.85

Published
2007

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