Now showing 1 - 3 of 3
  • Publication
    Semi-inclusive π0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS
    (2018-07-10)
    Jawalkar, S.
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    Koirala, S.
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    Avakian, H.
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    Bosted, P.
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    Griffioen, K. A.
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    Keith, C.
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    Kuhn, S. E.
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    Adhikari, K. P.
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    Adhikari, S.
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    Adikaram, D.
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    Akbar, Z.
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    Amaryan, M. J.
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    Anefalos Pereira, S.
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    Ball, J.
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    Baltzell, N. A.
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    Battaglieri, M.
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    Batourine, V.
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    Bedlinskiy, I.
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    Biselli, A. S.
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    Boiarinov, S.
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    Briscoe, W. J.
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    Brock, J.
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    Bültmann, S.
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    Burkert, V. D.
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    Cao, Frank Thanh
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    Carlin, C.
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    Carman, D. S.
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    Celentano, A.
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    Charles, G.
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    Chetry, T.
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    Ciullo, G.
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    Clark, L.
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    Colaneri, L.
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    Cole, P. L.
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    Contalbrigo, M.
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    Cortes, O.
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    Crede, V.
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    D'Angelo, A.
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    Dashyan, N.
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    De Vita, R.
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    De Sanctis, E.
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    Defurne, M.
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    Deur, A.
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    Djalali, C.
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    Ddoge, G.
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    Dupre, R.
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    Egiyan, H.
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    El Fassi, L.
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    Elouadrhiri, L.
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    Eugenio, P.
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    Fedotov, G.
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    Fegan, S.
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    Fersch, R.
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    Filippi, A.
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    Fleming, J. A.
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    Forest, T. A.
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    Fradi, A.
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    Garçon, M.
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    Ghandilyan, Y.
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    Gilfoyle, G. P.
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    Giovanetti, K. L.
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    Girod, F. X.
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    Gleason, C.
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    Gohn, W.
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    Golovatch, E.
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    Gothe, R. W.
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    Guidal, M.
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    Guler, N.
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    Guo, L.
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    Hanretty, C.
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    Harrison, N.
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    Hattawy, M.
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    Heddle, D.
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    Hicks, K.
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    Hollis, G.
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    Holtrop, M.
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    Hughes, S. M.
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    Ilieva, Y.
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    Ireland, D. G.
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    Ishkhanov, B. S.
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    Isupov, E. L.
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    Jenkins, D.
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    Jiang, H.
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    Joo, K.
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    Joosten, S.
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    Keller, D.
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    Khachatryan, G.
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    Khachatryan, M.
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    Khandaker, M.
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    Kim, A.
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    Kim, W.
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    Klein, A.
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    Klein, F. J.
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    Kubarovsky, V.
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    Lanza, L.
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    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 π0 X in multidimensional bins in four-momentum transfer (1.0 < Q 2 < 3.2 GeV2), Bjorken-x (0.12 < x < 0.48), hadron energy fraction (0.4 < z < 0.7), transverse pion momentum (0 < PT < 1.0 GeV), and azimuthal angle φh between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x and PT , which provide access to transverse-momentum distributions of longitudinally polarized quarks. The double spin asymmetries depend weakly on PT . The sin 2φh moments are zero within uncertainties, which is consistent with the expected suppression of the Collins fragmentation function. The observed sinφh moments suggest that quark gluon correlations are significant at large x.
    Scopus© Citations 10
  • Publication
    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
    (2018-05-04)
    Roy, P.
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    Akbar, Z.
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    Park, S.
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    Crede, V.
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    Anisovich, A. V.
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    Denisenko, I.
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    Klempt, E.
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    Nikonov, V. A.
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    Sarantsev, A. V.
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    Adhikari, K. P.
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    Adhikari, S.
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    Anefalos Pereira, S.
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    Ball, J.
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    Balossino, I.
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    Bashkanov, M.
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    Battaglieri, M.
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    Batourine, V.
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    Bedlinskiy, I.
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    Biselli, A. S.
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    Boiarinov, S.
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    Briscoe, W. J.
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    Brock, J.
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    Burkert, V. D.
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    Carlin, C.
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    Carman, D. S.
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    Celentano, A.
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    Charles, G.
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    Chetry, T.
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    Ciullo, G.
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    Clary, B. A.
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    Cole, P. L.
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    Contalbrigo, M.
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    D'Angelo, A.
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    Dashyan, N.
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    De Vita, R.
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    Deur, A.
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    Djalali, C.
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    Dugger, M.
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    Dupre, R.
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    El Fassi, L.
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    Elouadrhiri, L.
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    Eugenio, P.
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    Fedotov, G.
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    Fegan, S.
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    Filippi, A.
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    Fradi, A.
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    Gavalian, G.
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    Gevorgyan, N.
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    Gilfoyle, G. P.
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    Giovanetti, K. L.
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    Girod, F. X.
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    Gleason, C.
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    Gohn, W.
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    Golovatch, E.
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    Gothe, R. W.
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    Griffioen, K. A.
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    Guidal, M.
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    Guo, L.
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    Hafidi, K.
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    Hanretty, C.
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    Hattawy, M.
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    Hicks, K.
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    Holtrop, M.
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    Ilieva, Y.
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    Ireland, D. G.
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    Ishkhanov, B. S.
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    Isupov, E. L.
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    Jenkins, D.
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    Joo, K.
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    Joosten, S.
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    Keith, C. D.
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    Keller, D.
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    Khachatryan, G.
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    Khandaker, M.
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    Kim, A.
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    Kim, W.
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    Klein, A.
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    Klein, F. J.
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    Kubarovsky, V.
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    Lanza, L.
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    Lenisa, P.
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    Livingston, K.
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    Lu, H. Y.
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    Macgregor, I. J.D.
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    Markov, N.
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    Mayer, M.
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    McCracken, M. E.
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    McKinnon, B.
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    Meekins, D. G.
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    Meyer, C. A.
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    Meziani, Z. E.
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    Mokeev, V.
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    Montgomery, R. A.
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    Movsisyan, A.
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    Munoz Camacho, C.
    The photoproduction of ω mesons off the proton has been studied in the reaction γp → p ω 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 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.
    Scopus© Citations 9
  • Publication
    Longitudinal target-spin asymmetries for deeply virtual compton scattering
    (2015-01-22)
    Seder, E.
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    Biselli, A.
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    Pisano, S.
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    Niccolai, S.
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    Smith, G. D.
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    Joo, K.
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    Adhikari, K.
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    Amaryan, M. J.
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    Anderson, M. D.
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    Anefalos Pereira, S.
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    Avakian, H.
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    Battaglieri, M.
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    Bedlinskiy, I.
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    Bono, J.
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    Boiarinov, S.
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    Bosted, P.
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    Briscoe, W.
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    Brock, J.
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    Bültmann, S.
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    Burkert, V. D.
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    Carman, D. S.
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    Carlin, C.
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    Celentano, A.
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    Chandavar, S.
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    Charles, G.
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    Colaneri, L.
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    Cole, P. L.
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    Contalbrigo, M.
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    Crabb, D.
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    Crede, V.
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    D'Angelo, A.
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    Dashyan, N.
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    De Vita, R.
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    De Sanctis, E.
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    Deur, A.
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    Djalali, C.
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    Doughty, D.
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    Dupre, R.
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    El Fassi, L.
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    Elouadrhiri, L.
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    Eugenio, P.
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    Fedotov, G.
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    Fegan, S.
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    Filippi, A.
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    Fleming, J. A.
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    Fradi, A.
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    Garillon, B.
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    Garçon, M.
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    Gevorgyan, N.
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    Ghandilyan, Y.
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    Giovanetti, K. L.
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    Girod, F. X.
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    Goetz, J. T.
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    Gohn, W.
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    Gothe, R. W.
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    Griffioen, K. A.
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    Guegan, B.
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    Guidal, M.
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    Guo, L.
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    Hafidi, K.
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    Hanretty, C.
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    Harrison, N.
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    Hattawy, M.
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    Hirlinger Saylor, N.
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    Holtrop, M.
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    Hughes, S. M.
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    Ilieva, Y.
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    Ireland, D. G.
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    Ishkhanov, B. S.
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    Isupov, E. L.
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    Jo, H. S.
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    Joosten, S.
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    Keith, C. D.
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    Keller, D.
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    Khachatryan, G.
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    Khandaker, M.
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    Kim, A.
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    Kim, W.
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    Klein, A.
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    Klein, F. J.
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    Koirala, S.
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    Kubarovsky, V.
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    Kuhn, S. E.
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    Lenisa, P.
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    Livingston, K.
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    Lu, H. Y.
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    Macgregor, I. J.D.
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    Markov, N.
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    Mayer, M.
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    McKinnon, B.
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    Meekins, D. G.
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    Mirazita, M.
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    Mokeev, V.
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    Montgomery, R.
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    Moody, C. I.
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    Moutarde, H.
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    Movsisyan, A.
    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e0 p0 γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.
    Scopus© Citations 48