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

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

doi:10.1016/j.physletb.2018.06.014

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<3.2 GeV2), Bjorken-x (0.12<0.48), hadron energy fraction (0.4<0.7), transverse pion momentum (0<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 sin⁡ϕh moments suggest that quark gluon correlations are significant at large x.

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

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

2018-01-01

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<3.2 GeV2), Bjorken-x (0.12<0.48), hadron energy fraction (0.4<0.7), transverse pion momentum (0<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 sin⁡ϕh moments suggest that quark gluon correlations are significant at large x.