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

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

doi:10.1103/PhysRevC.97.055202

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.

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

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

2018-01-01

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.