1. Measurement of the helicity asymmetry $\mathbb{E}$ for the $\vec{\gamma}\vec{p} \to p \pi^0$ reaction in the resonance region
- Author
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Kim, C.W, Zachariou, N, Bashkanov, M, Briscoe, W.J, Fegan, S, Kashevarov, V.L, Nikonov, K, Sarantsev, A, Schmidt, A, Strakovsky, I.I, Watts, D.P, Workman, R.L, Achenbach, P, Akbar, Z, Amaryan, M.J, Angelini, G, Armstrong, W.R, Atac, H, Baashen, L, Baltzell, N.A, Barion, L, Battaglieri, M, Bedlinskiy, I, Benkel, B, Benmokhtar, F, Benmouna, N, Bianconi, A, Biselli, A.S, Booth, W.A, Bossù, F, Boiarinov, S, Brinkmann, K.T, Brock, J, Bulumulla, D, Burkert, V.D, Cao, T, Carlin, C, Carman, D.S, Carvajal, J.C, Chatagnon, P, Chesnokov, V, Chetry, T, Ciullo, G, Clash, G, Cole, P.L, Contalbrigo, M, Becerra, O. Cortes, Costantini, G, Crede, V, d'Angelo, A, Dashyan, N, de Vita, R, Defurne, M, Deur, A, Diehl, S, Djalali, C, Dugger, M, Dupre, R, Egiyan, H, Alaoui, A. El, Fassi, L. El, Elouadrhiri, L, Eugenio, P, Filippi, A, Fogler, C, Gavalian, G, Gilfoyle, G.P, Golubenko, A.A, Gosta, G, Gothe, R.W, Griffioen, K.A, Hafidi, K, Hakobyan, H, Hattawy, M, Hauenstein, F, Hayward, T.B, Heddle, D, Hobart, A, Holtrop, M, Ilieva, Y, Illari, I, Ireland, D.G, Isupov, E.L, Iwamoto, H, Jenkins, D, Jo, H.S, Johnston, R, Joo, K, Joosten, S, Kageya, T, Keith, C.D, Keller, D, Khanal, A, Kim, A, Kim, W, Klein, F.J, Klimenko, V, Kripko, A, Kubarovsky, V, Lanza, L, Leali, M, Lee, S, Li, X, Livingston, K, Macgregor, I.J.D, Marchand, D, Mascagna, V, Mckinnon, B, Migliorati, S, Milner, R.G, Mineeva, T, Mokeev, V, Munoz Camacho, C, Nadel-Turonski, P, Neupane, K, Niccolai, S, Osipenko, M, Ostrovidov, A.I, Pandey, P, Paolone, M, Pappalardo, L.L, Paremuzyan, R, Pasyuk, E, Paul, S.J, Pilleux, N, Pokhrel, M, Poudel, J, Price, J.W, Prok, Y, Radic, A, Ramasubramanian, N, Ratliff, S, Reed, T, Richards, J, Ripani, M, Ritchie, B.G, Ritman, J, Rosner, G, Salgado, C, Schadmand, S, Schott, D, Schumacher, R.A, Scott, M.B.C, Seely, M.L, Seroka, E.M, Shirokov, E.V, Shrestha, U, Sokhan, D, Sparveris, N, Spreafico, M, Strauch, S, Tan, J, Tyson, R, Ungaro, M, Vallarino, S, Venturelli, L, Voskanyan, H, Voutier, E, Wei, X, Williams, R, Wishart, R, Wood, M.H, Yurov, M, Zhang, J, Zurek, M, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), and CLAS
- Subjects
sum rule ,beam, energy ,helicity, asymmetry ,CLAS ,multipole ,GeV ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,photon, beam ,Nuclear Experiment - Abstract
The double-spin-polarization observable $\mathbb{E}$ for $\vec{\gamma}\vec{p}\to p\pi^0$ has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies $E_\gamma$ from 0.367 to $2.173~\mathrm{GeV}$ (corresponding to center-of-mass energies from 1.240 to $2.200~\mathrm{GeV}$) for pion center-of-mass angles, $\cos\theta_{\pi^0}^{c.m.}$, between -0.86 and 0.82. These new CLAS measurements cover a broader energy range and have smaller uncertainties compared to previous CBELSA data and provide an important independent check on systematics. These measurements are compared to predictions as well as new global fits from The George Washington University, Mainz, and Bonn-Gatchina groups. Their inclusion in multipole analyses will refine our understanding of the single-pion production contribution to the Gerasimov-Drell-Hearn sum rule and improve the determination of resonance properties., Comment: 11 pages, 5 figures
- Published
- 2023