First CLAS12 Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries in the Extended Valence Region

Christiaens, G; Defurne, M; Sokhan, D; Achenbach, P; Akbar, Z; Amaryan, M J; Atac, H; Avakian, H; Gayoso, C Ayerbe; Baashen, L; Baltzell, N A; Barion, L; Bashkanov, M; Battaglieri, M; Bedlinskiy, I; Benkel, B; Benmokhtar, F; Bianconi, A; Biselli, A S; Bondi, M; Booth, W A; Bossù, F; Boiarinov, S; Brinkmann, K-Th; Briscoe, W J; Bueltmann, S; Bulumulla, D; Burkert, V D; Cao, T; Carman, D S; Carvajal, J C; Celentano, A; Chatagnon, P; Chesnokov, V; Chetry, T; Ciullo, G; Clash, G; Cole, P L; Contalbrigo, M; Costantini, G; D'Angelo, A; Dashyan, N; De Vita, R; Deur, A; Diehl, S; Dilks, C; Djalali, C; Dupre, R; Egiyan, H; Ehrhart, M; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Fegan, S; Filippi, A; Gates, K; Gavalian, G; Ghandilyan, Y; Gilfoyle, G P; Girod, F X; Glazier, D I; Golubenko, A A; Gosta, G; Gothe, R W; Gotra, Y; Griffioen, K A; Guidal, M; Hafidi, K; Hakobyan, H; Hattawy, M; Hauenstein, F; Hayward, T B; Heddle, D; Hobart, A; Holmberg, D E; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; H S, Jo; Keller, D; Khachatryan, M; Khanal, A; Kim, W; Kripko, A; Kubarovsky, V; Kuhn, S E; Lagerquist, V; Lanza, L; Kabir, M L; Leali, M; Lee, S; Lenisa, P; Li, X; Livingston, K; Macgregor, I J D; Marchand, D; Mascagna, V; Matousek, G; Mckinnon, B; Mclauchlin, C; Meziani, Z E; Migliorati, S; Milner, R G; Mineeva, T; Mirazita, M; Mokeev, V; Molina, E; Camacho, C Munoz; Nadel-Turonski, P; Naidoo, P; Neupane, K; Niccolai, S; Nicol, M; Niculescu, G; Osipenko, M; Ouillon, M; Pandey, P; Paolone, M; Pappalardo, L L; Paremuzyan, R; Pasyuk, E; Paul, S J; Phelps, W; Pilleux, N; Pokhrel, M; Poudel, J; Price, J W; Prok, Y; Radic, A; Ramasubramanian, N; Raue, B A; Reed, Trevor; Richards, J; Ripani, M; Ritman, J; Rossi, P; Sabatié, F; Salgado, C; Schadmand, S; Schmidt, A; Scott, M B C; Sharabian, Y G; Shirokov, E V; Shrestha, U; Simmerling, P; Sparveris, N; Spreafico, M; Stepanyan, S; Strakovsky, I I; Strauch, S; Tan, J A; Trotta, N; Turisini, M; Tyson, R; Ungaro, M; Vallarino, S; Venturelli, L; Voskanyan, H; Voutier, E; Watts, D P; Wei, X; Williams, R; Wishart, R; Wood, M H; Zachariou, N; Zhang, J; Zhao, Z W; Ziegler, V; Zurek, M

doi:10.1103/PhysRevLett.130.211902

Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarized protons. The results greatly extend the Q2 and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.