Differential cross sections of the exclusive process ep -> e 'pi(+)n were measured with good precision in the range of the photon virtuality Q(2) = 1.8-4.5 GeV2 and the invariant mass range of the pi(+)n final state W = 1.6-2.0 GeV using the Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer. Data were collected with nearly complete coverage in the azimuthal and polar angles of the n pi(+) center-of-mass system. More than 37 000 cross-section points were measured. The contributions of the isospin I = 1/2 resonances N(1675) 5/2(-), N(1680) 5/2(+), and N(1710) 1/2(+) were extracted at different values of Q(2) using a single-channel, energy-dependent resonance amplitude analysis. Two different approaches, the unitary isobar model and the fixed-t dispersion relations, were employed in the analysis. We observe significant strength of the N(1675)5/2(-) in the A(1/2) amplitude, which is in strong disagreement with quark models that predict both transverse amplitudes to be strongly suppressed. For the N(1680)5/2(+) we observe a slow changeover from the dominance of the A(3/2) amplitude at the real photon point (Q(2) = 0) to a Q(2) where A(1/2) begins to dominate. The scalar amplitude S-1/2 drops rapidly with Q(2) consistent with quark model prediction. For the N(1710)1/2(+) resonance our analysis shows significant strength for the A1/2 amplitude at Q(2) < 2.5 GeV2.
Park, K., Aznauryan, I.g., Burkert, V.d., Adhikari, K.p., Amaryan, M.j., Pereira, S.a., et al. (2015). Measurements of ep→e′π+nat1.6<W<2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS. PHYSICAL REVIEW. C, NUCLEAR PHYSICS, 91(4) [10.1103/PhysRevC.91.045203].
Tipologia: | Articolo su rivista | |
Citazione: | Park, K., Aznauryan, I.g., Burkert, V.d., Adhikari, K.p., Amaryan, M.j., Pereira, S.a., et al. (2015). Measurements of ep→e′π+nat1.6<W<2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS. PHYSICAL REVIEW. C, NUCLEAR PHYSICS, 91(4) [10.1103/PhysRevC.91.045203]. | |
URL: | https://link.aps.org/accepted/10.1103/PhysRevC.91.045203 | |
Altre informazioni significative: | CLAS Collaboration | |
IF: | Con Impact Factor ISI | |
Lingua: | English | |
Settore Scientifico Disciplinare: | Settore FIS/04 - Fisica Nucleare e Subnucleare | |
Revisione (peer review): | Esperti anonimi | |
Tipo: | Articolo | |
Rilevanza: | Rilevanza internazionale | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevC.91.045203 | |
Stato di pubblicazione: | Pubblicato | |
Data di pubblicazione: | 13-apr-2015 | |
Titolo: | Measurements of ep→e′π+nat1.6<W<2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS | |
Autori: | ||
Autori: | Park, K; Aznauryan, Ig; Burkert, Vd; Adhikari, Kp; Amaryan, Mj; Pereira, Sa; Avakian, H; Battaglieri, M; Badui, R; Bedlinskiy, I; Biselli, As; Bono, J; Briscoe, Wj; Brooks, Wk; Carman, Ds; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, Pl; Contalbrigo, M; Cortes, O; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; Egiyan, H; Alaoui, Ae; Elouadrhiri, L; Fassi, Le; Eugenio, P; Fedotov, G; Fegan, S; Fersch, R; Filippi, A; Fleming, Ja; Garillon, B; Garçon, M; Gevorgyan, N; Gilfoyle, Gp; Giovanetti, Kl; Girod, Fx; Joo, Hs; Goetz, Jt; Golovatch, E; Gothe, Rw; Griffioen, Ka; Guegan, B; Guidal, M; Guo, L; Hakobyan, H; Hanretty, C; Hattawy, M; Hicks, K; Holtrop, M; Hughes, Sm; Hyde, Ce; Ilieva, Y; Ireland, Dg; Ishkhanov, Bs; Isupov, El; Jenkins, D; Jiang, H; Jo, Hs; Joo, K; Joosten, S; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, Fj; Kubarovsky, V; Kuhn, Se; Kuleshov, Sv; Lenisa, P; Livingston, K; Lu, Hy; Macgregor, Ijd; Markov, N; Martinez, D; Mckinnon, B; Mokeev, V; Montgomery, Ra; Moutarde, H; Camacho, Cm; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, Ai; Paolone, M; Pasyuk, E; Peng, P; Phelps, W; Phillips, Jj; Pisano, S; Pogorelko, O; Price, Jw; Procureur, S; Prok, Y; Protopopescu, D; Puckett, Ajr; Raue, Ba; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, Ra; Seder, E; Sharabian, Yg; Simonyan, A; Skorodumina, I; Smith, Es; Smith, Gd; Sparveris, N; Stoler, P; Strakovsky, Ii; Strauch, S; Sytnik, V; Taiuti, M; Tang, W; Taylor, Ce; Tian, Y; Trivedi, A; Ungaro, M; Voskanyan, H; Voutier, E; Walford, Nk; Watts, Dp; Wei, X; Weinstein, Lb; Wood, Mh; Zachariou, N; Zana, L; Zhang, J; Zhao, Zw; Zonta, I | |
Appare nelle tipologie: | 01 - Articolo su rivista |