Year: 2021
Type: article
Abstract: We present the first measurement of the timelike Compton scattering process, $\ensuremath{\gamma}p\ensuremath{\rightarrow}{p}^{\ensuremath{'}}{\ensuremath{\gamma}}^{*}({\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}})$, obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities $2.25<{Q}^{\ensuremath{'}2}<9\text{ }\text{ }{\mathrm{GeV}}^{2}$, squared momentum transferred $0.1<\ensuremath{-}t<0.8\text{ }\text{ }{\mathrm{GeV}}^{2}$, and average total center-of-mass energy squared $s=14.5\text{ }\text{ }{\mathrm{GeV}}^{2}$. The photon beam polarization asymmetry, similar to the beam-spin asymmetry in deep virtual Compton scattering, is sensitive to the imaginary part of the Compton form factors and provides a way to test the universality of the generalized parton distributions. The angular asymmetry of the decay leptons accesses the real part of the Compton form factors and thus the $D$-term in the parametrization of the generalized parton distributions.
Source: Physical Review Letters
Authors: P. Chatagnon, S. Niccolai, S. Stepanyan, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, C. Ayerbe Gayoso, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, L. Biondo, A. S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W. J. Briscoe, W. K. Brooks, D. Bulumulla, V. D. Burkert, D. S. Carman, J. C. Carvajal, M. Caudron, A. Celentano, T. Chetry, G. Ciullo, L. Clark, P. L. Cole, M. Contalbrigo, G. Costantini, V. Crede, A. D’Angelo, N. Dashyan, M. Defurne, R. De Vita, A. Deur, S. Diehl, C. Djalali, R. Dupré, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, R. Fersch, A. Filippi, G. Gavalian, Y. Ghandilyan, G. P. Gilfoyle, F. X. Girod, D. I. Glazier, A. A. Golubenko, R. W. Gothe, Y. Gotra, K. A. Griffioen, M. Guidal, L. Guo, H. Hakobyan, M. Hattawy, T. B. Hayward, D. Heddle, A. Hobart, M. Holtrop, C. E. Hyde, Y. Ilieva, D. G. Ireland, E. L. Isupov, H. S. Jo, K. Joo, M. L. Kabir, D. Keller, G. Khachatryan, A. Khanal, A. Kim, W. Kim, A. Kripko, V. Kubarovsky, S. E. Kuhn, L. Lanza, M. Leali, S. Lee, P. Lenisa, K. Livingston, I. J. D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, C. McLauchlin, S. Migliorati, M. Mirazita, V. Mokeev, R. A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, T. R. O’Connell, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L. L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J. Poudel, J. W. Price, Y. Prok, B. A. Raue, T. Reed, M. Ripani, A. Rizzo, P. Rossi, J. Rowley, F. Sabatié, A. Schmidt, E. P. Segarra, Y. G. Sharabian, E. V. Shirokov, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, I. I. Strakovsky, S. Strauch, N. Tyler, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, A. Vossen, E. Voutier, D. P. Watts, K. Wei, X. Wei, R. Wishart, B. Yale, N. Zachariou, J. Zhang, Z. W. Zhao
Institutions: Centre National de la Recherche Scientifique, Université Paris-Saclay, Institut National de Physique Nucléaire et de Physique des Particules, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie, Thomas Jefferson National Accelerator Facility, Old Dominion University, George Washington University, Argonne National Laboratory, Temple University, William & Mary, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, University of York, Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Kurchatov Institute, Duquesne University, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, University of Brescia, University of Messina, Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Fairfield University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut de Recherche sur les Lois Fondamentales de l'Univers, Universidad Técnica Federico Santa María, Florida International University, Ohio University, Mississippi State University, University of Ferrara, University of Glasgow, Lamar University, Florida State University, University of Rome Tor Vergata, Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata, A. Alikhanyan National Laboratory, University of Connecticut, Justus-Liebig-Universität Gießen, Christopher Newport University, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, University of Richmond, Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, University of South Carolina, University of New Hampshire, Kyungpook National University, University of Virginia, Massachusetts Institute of Technology, University of Insubria, Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, New Mexico State University, California State University, Dominguez Hills, Duke University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funders: National Science Foundation, U.S. Department of Energy, European Commission, National Research Foundation, National Research Foundation of Korea, Centre National de la Recherche Scientifique, Ministry of Science and Higher Education of the Russian Federation, Istituto Nazionale di Fisica Nucleare, Horizon 2020 Framework Programme, Science and Technology Facilities Council, Instituto Nazionale di Fisica Nucleare, Thomas Jefferson National Accelerator Facility
Awards: Nuclear Physics Consolidated Grant, G1728142190, G2263355576, G2702141073, Nuclear Physics Consolidated Grant 21-24 - University of York, G2988778103, Nuclear Physics Consolidated Grant, The strong interaction at the frontier of knowledge: fundamental research and applications, ELECTRON DETECTOR FOR THE JEFFERSON LAB HALL C COMPTON POLARIMETER, G3518886221, G434337789, G4824140319, G5340680269, Shining a light on strangeness, Nuclear Physics Consolidated Grant, Shining a light on strangeness, Transfer of Research Grant Funds (from ST/P004008/1 to ST/P003885/1), G7451223319, G7520763071, Nuclear Physics Consolidated Grant, Jefferson Lab project grant, G8462202600, Engaging Education with Binding Blocks, Hunt for Exotic Particles: Dibaryons, Spectator Tagging Experiments to Understand the Structure of Matter
OpenAlex ID: W4200417405