Measurement of the helicity asymmetry E for the γ p → pπ0 reaction in the resonance region

Kim, C. W. et al. (2023) Measurement of the helicity asymmetry E for the γ p → pπ0 reaction in the resonance region. European Physical Journal A, 59(9), 217. (doi: 10.1140/epja/s10050-023-01123-3)

Abstract

The double-spin-polarization observable E for gamma p -> p pi0 has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies from 0.367 to 2.137 GeV (corresponding to center-of-mass energies from 1.240 to 2.200 GeV) for pion center-of-mass angles, cos(theta) 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 allow us to refine our understanding of the single-pion production contribution to the Gerasimov-Drell-Hearn sum rule and improve the determination of resonance properties, which will be presented in a future publication.

• Item Type: Articles
• Additional Information: This work was supported in part by the U. S. Department of Energy, Office of Science, Office of Nuclear Physics under Awards No. DE–SC0016583 and DE–SC0016582; by the U. K. Science and Technology Facilities Council grants, ST/P004385/2, ST/T002077/1, ST/V001035/1, ST/V002570/1, and ST/L00478X/2; by the EU Horizon 2020 research by innovation program, STRONG–2020 project (under grant agreement No. 824093), as well as by the Russian Science Foundation RSF22–22–00722 grant. We also acknowledge the outstanding efforts of the staff of the Accelerator and Physics Divisions at Jefferson Lab that made this experiment possible. The Southeastern Universities Research Association (SURA) operated the Thomas Jefferson National Accelerator Facility for the United States Department of Energy under contract DE–AC05–06OR23177. Further support was provided by the National Science Foundation, the Italian Istituto Nazionale di Fisica Nucleare, the Chilean Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), the Chilean Agency of Research and Development (ANID), the French Centre National de la Recherche Scientifique, the French Commissariat à l’Energie Atomique, and the National Research Foundation of Korea.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sokhan, Dr Daria and McKinnon, Dr Bryan and Wishart, Robert and Tyson, Richard and Ireland, Professor David and Livingston, Dr Kenneth and MacGregor, Professor Douglas and Rosner, Professor Guenther
• Authors: 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. C., 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. E., Fassi, L. E., 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., Camacho, C. M., 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., and Zurek, M.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Research Group: Nuclear and Hadron Physics
• Journal Name: European Physical Journal A
• Publisher: Springer
• ISSN: 1434-6001
• ISSN (Online): 1434-601X
• Published Online: 26 September 2023
• Copyright Holders: Copyright © The Author(s) 2023
• First Published: First published in European Physical Journal A 59(9):217
• Publisher Policy: Reproduced under a Creative Commons license

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
					824093