Measurement of deeply virtual Compton scattering off $^{4}\mathrm{He}$ with the CEBAF Large Acceptance Spectrometer at Jefferson Lab

Autor: Dupré, R., Hattawy, M., Baltzell, N.A., Bültmann, S., de Vita, R., El Alaoui, A., El Fassi, L., Egiyan, H., Girod, F.X., Guidal, M., Hafidi, K., Jenkins, D., Liuti, S., Perrin, Y., Stepanyan, S., Torayev, B., Voutier, E., Amaryan, M.J., Armstrong, W.R., Atac, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A.S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W.J., Bulumulla, D., Burkert, V., Carman, D.S., Carvajal, J.C., Caudron, M., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clary, B.A., Cole, P.L., Contalbrigo, M., Costantini, G., Crede, V., d'Angelo, A., Dashyan, N., Defurne, M., Deur, A., Diehl, S., Djalali, C., Ehrhart, M., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Forest, T.A., Ghandilyan, Y., Gilfoyle, G.P., Gothe, R.W., Griffioen, K.A., Hakobyan, H., Hayward, T.B., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D.G., Isupov, E.L., Jo, H.S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khanal, A., Khandaker, M., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S.E., Lanza, L., Livingston, K., Kabir, M.L., Leali, M., Lenisa, P., Macgregor, I.J.D., Marchand, D., Markov, N., Mascagna, V., Mayer, M., Mckinnon, B., Mirazita, M., Mokeev, V.I., Neupane, K., Niccolai, S., O'Connell, T.R., Osipenko, M., Paolone, M., Pappalardo, L.L., Paremuzyan, R., Pasyuk, E., Payette, D., Phelps, W., Pivnyuk, N., Pogorelko, O., Poudel, J., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R., Sergeyeva, V., Sharabian, Y., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I.I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Watts, D., Wei, K., Wei, X., Weinstein, L.B., Wishart, R., Wood, M.H., Yale, B., Zachariou, N., Zhang, J.
Přispěvatelé: Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Phys.Rev.C
Phys.Rev.C, 2021, 104 (2), pp.025203. ⟨10.1103/PhysRevC.104.025203⟩
Popis: International audience; We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off He4 using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized He4 gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling He4 nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the coherent (eHe4→e′He4′γ′) beam spin asymmetries compared to those observed on the free proton, while the incoherent (eHe4→e′p′γ′X′) asymmetries exhibit a 30% suppression. From the coherent data, we were able to extract, in a model-independent way, the real and imaginary parts of the only He4 Compton form factor, HA, leading the way toward 3D imaging of the partonic structure of nuclei.
Databáze: OpenAIRE
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