학술논문
Extraction of beam-spin asymmetries from the hard exclusive $\pi^{+}$ channel off protons in a wide range of kinematics
Document Type
Working Paper
Author
Diehl, S.; Joo, K.; Kim, A.; Avakian, H.; Kroll, P.; Park, K.; Riser, D.; Semenov-Tian-Shansky, K.; Tezgin, K.; Adhikari, K. P.; Adhikari, S.; Amaryan, M. J.; Angelini, G.; Asryan, G.; Atac, H.; Barion, L.; Battaglieri, M.; Bedlinskiy, I.; Benmokhtar, F.; Bianconi, A.; Biselli, A. S.; Boss`u, F.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Bulumulla, D.; Burkert, V. D.; Carman, D. S.; Carvajal, J. C.; Celentano, A.; Chatagnon, P.; Chetry, T.; Ciullo, G.; Clark, L.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; Defurne, M.; Deur, A.; Dilks, C.; Djalali, C.; Dupre, R.; Egiyan, H.; Ehrhart, M.; Alaoui, A. El; Fassi, L. El; Eugenio, P.; Filippi, A.; Forest, T. A.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hayward, T. B.; Heddle, D.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, M.; Khanal, A.; Khandaker, M.; Kim, C. W.; Kim, W.; Kubarovsky, V.; Kuhn, S. E.; Lanza, L.; Leali, M.; Lenisa, P.; Livingston, K.; MacGregor, I. J. D.; Marchand, D.; Markov, N.; Marsicano, L.; Mascagna, V.; McKinnon, B.; Meziani, Z. E.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Camacho, C. Munoz; Nadel-Turonski, P.; Niculescu, G.; Osipenko, M.; Paolone, M.; Pappalardo, L. L.; Pasyuk, E.; Phelps, W.; Pogorelko, O.; Price, J. W.; Prok, Y.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rossi, P.; Rowley, J.; Sabatie, F.; Salgado, C.; Schmidt, A.; Schumacher, R. A.; Sharabian, Y. G.; Shrestha, U.; Soto, O.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Tan, J. A.; Tyler, N.; Ungaro, M.; Venturelli, L.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zhao, Z. W.
Source
Phys. Rev. Lett. 125, 182001 (2020)
Subject
Language
Abstract
We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.