학술논문
Measurement of the helicity asymmetry Eγ→p→→pπ0 for the Eγ→p→→pπ0 reaction in the resonance region: The CLAS Collaboration
Document Type
Original Paper
Author
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.; Camacho, C. Munoz; 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.
Source
The European Physical Journal A: Hadrons and Nuclei. 59(9)
Subject
Language
English
ISSN
1434-601X
Abstract
The double-spin-polarization observable Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.- for Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.- has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.- from 0.367 to Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.- (corresponding to center-of-mass energies from 1.240 to Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.-) for pion center-of-mass angles, Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.-, between Eγ→p→→pπ0Eγ2.173GeV2.200GeVcosθπ0c.m.- 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.