A multidimensional study of the structure function ratio from hard exclusive ??+ electro-production off protons in the GPD regime

Diehl, S.; Kim, A.; Joo, K.; Achenbach, P.; Akbar, Z.; Amaryan, M. J.; Atac, H.; Avagyan, H.; Ayerbe Gayoso, C.; Baashen, L.; Barion, L.; Bashkanov, M.; Battaglieri, M.; Bedlinskiy, I.; Benkel, B.; Benmokhtar, F.; Bianconi, A.; Biselli, A. S.; Bondi, M.; Booth, W. A.; Boss??, F.; Boiarinov, S.; Brinkmann, K. -Th.; Briscoe, W. J.; Bueltmann, S.; Bulumulla, D.; Burkert, V. D.; Carman, D. S.; 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.; Defurne, M.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; Ehrhart, M.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Fegan, S.; Filippi, A.; Gavalian, G.; Ghandilyan, Y.; Gilfoyle, G. P.; Glazier, D. I.; Golubenko, A. A.; Gosta, G.; Gothe, R. W.; Gotra, Y.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hakobyan, H.; Hattawy, M.; Hayward, T. B.; Heddle, D.; Hobart, A.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Isupov, E. L.; H. S., Jo; Khachatryan, M.; Khanal, A.; Kim, W.; Kripko, A.; Kubarovsky, V.; Lagerquist, V.; Laget, J. -M.; Lanza, L.; Leali, M.; Lee, S.; Lenisa, P.; Li, X.; Livingston, K.; Macgregor, I. J . D.; Marchand, D.; Mascagna, V.; Mckinnon, B.; Meziani, Z. E.; Migliorati, S.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Molina, E.; Montgomery, R. A.; Munoz Camacho, C.; 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.; Reed, T.; Richards, J.; Ripani, M.; Ritman, J.; Rossi, P.; Sabati??, F.; Salgado, C.; Schadmand, S.; Schmidt, A.; Sharabian, Y.; Shirokov, E. V.; Shrestha, U.; Simmerling, P.; Sokhan, D.; 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.; Zurek, M.

doi:10.1016/j.physletb.2023.137761

A multidimensional extraction of the structure function ratio sigma(LT')/sigma(0) from the hard exclusive (e) over right arrowp -> e'n pi(+) reaction above the resonance region has been performed. The study was done based on beamspin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime (t/Q(2) << 1) with a wide kinematic range of x(B) in the valence regime (0.17 < x(B) < 0.55), and virtualities Q(2) << ranging from 1.5 GeV2 up to 6 GeV2. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low Q(2), while the GPD model is more appropriate at high Q(2). (c) 2023 The Author(s). Published by Elsevier B.V.