Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(+) electroproduction reaction. gamma(*) p -> n pi(+). The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q(2) < 6 GeV2. Results were obtained for about 6000 bins in W, Q(2), cos(theta(*)), and phi(*). Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W. A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results 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.

Bosted, P.e., Amaryan, M.j., Anefalos Pereira, S., Avakian, H., Badui, R.a., Ball, J., et al. (2017). Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1 GeV2. I. ep→eπ+n. PHYSICAL REVIEW C, 95(3), 1-12 [10.1103/PhysRevC.95.035206].

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

COLANERI, LUCA;D'ANGELO, ANNALISA;ZONTA, IRENE
2017-03-20

Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(+) electroproduction reaction. gamma(*) p -> n pi(+). The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q(2) < 6 GeV2. Results were obtained for about 6000 bins in W, Q(2), cos(theta(*)), and phi(*). Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W. A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results 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.
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/04 - Fisica Nucleare e Subnucleare
English
Con Impact Factor ISI
FORM-FACTOR; MESONS; CLAS; Q2
https://journals.aps.org/prc/pdf/10.1103/PhysRevC.95.035206
Bosted, P.e., Amaryan, M.j., Anefalos Pereira, S., Avakian, H., Badui, R.a., Ball, J., et al. (2017). Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1 GeV2. I. ep→eπ+n. PHYSICAL REVIEW C, 95(3), 1-12 [10.1103/PhysRevC.95.035206].
Bosted, P; Amaryan, M; Anefalos Pereira, S; Avakian, H; Badui, R; Ball, J; Baltzell, N; Battaglieri, M; Batourine, V; Bedlinskiy, I; Biselli, A; Briscoe, W; Bultmann, S; Burkert, V; Carman, D; Celentano, A; Chandavar, S; Charles, G; Ciullo, G; Clark, L; Colaneri, L; Cole, P; Contalbrigo, M; Crede, V; D'Angelo, A; De Vita, R; Deur, A; De Sanctis, E; Djalali, C; Dupre, R; Egiyan, H; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fanchini, E; Fedotov, G; Filippi, A; Fleming, J; Forest, T; Fradi, A; Gevorgyan, N; Ghandilyan, Y; Gilfoyle, G; Girod, F; Gleason, C; Gohn, W; Golovatch, E; Gothe, R; Griffioen, K; Guidal, M; Hakobyan, H; Hattawy, M; Hicks, K; Holtrop, M; Hughes, S; Ilieva, Y; Ireland, D; Ishkhanov, B; Isupov, E; Jiang, H; Jo, H; Joo, K; Joosten, S; Khachatryan, G; Khandaker, M; Kim, A; Kim, W; Klein, F; Koirala, S; Kubarovsky, V; Kuhn, S; Lanza, L; Net, L; Lenisa, P; Livingston, K; Macgregor, I; Mccracken, M; Mckinnon, B; Meyer, C; Mirazita, M; Mokeev, V; Montgomery, R; Munevar, E; Munoz Camacho, C; Murdoch, G; Nadel Turonski, P; Niccolai, S; Osipenko, M; Ostrovidov, A; Park, K; Pasyuk, E; Peng, P; Phelps, W; Pisano, S; Pogorelko, O; Price, J; Prok, Y; Protopopescu, D; Puckett, A; Raue, B; Ripani, M; Rosner, G; Rossi, P; Schumacher, R; Seder, E; Skorodumina, I; Smith, G; Sokhan, D; Sparveris, N; Stankovic, I; Stepanyan, S; Strakovsky, I; Strauch, S; Taiuti, M; Tian, Y; Torayev, B; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N; Wei, X; Weinstein, L; Zachariou, N; Zhang, J; Zhao, Z; Zonta, I
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/181145
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 5
  • ???jsp.display-item.citation.isi??? 5
social impact