Journal article

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


Authors listKim, 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.; Bossu, 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.; El Alaoui, A.; El Fassi, L.; 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.

Publication year2023

JournalThe European Physical Journal A

Volume number59

Issue number9

ISSN1434-6001

eISSN1434-601X

DOI Linkhttps://doi.org/10.1140/epja/s10050-023-01123-3

PublisherSpringer


Abstract
The double-spin-polarization observable E for gamma(->) p(->) -> p pi(0) 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 GeV (corresponding to center-of mass energies from 1.240 to 2.200 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 multi pole analyses will allow us to refine our understanding of the single-pion production contribution to the Gerasimov-DrellHearn sum rule and improve the determination of resonance properties, which will be presented in a future publication.



Citation Styles

Harvard Citation styleKim, C., Zachariou, N., Bashkanov, M., Briscoe, W., Fegan, S., Kashevarov, V., et al. (2023) Measurement of the helicity asymmetry E for the γ p → pπ0 reaction in the resonance region, The European Physical Journal A, 59(9), Article 217. https://doi.org/10.1140/epja/s10050-023-01123-3

APA Citation styleKim, C., Zachariou, N., Bashkanov, M., Briscoe, W., Fegan, S., Kashevarov, V., Nikonov, K., Sarantsev, A., Schmidt, A., Strakovsky, I., Watts, D., Workman, R., Achenbach, P., Akbar, Z., Amaryan, M., Angelini, G., Armstrong, W., Atac, H., Baashen, L., ...Zurek, M. (2023). Measurement of the helicity asymmetry E for the γ p → pπ0 reaction in the resonance region. The European Physical Journal A. 59(9), Article 217. https://doi.org/10.1140/epja/s10050-023-01123-3



Keywords


1ST MEASUREMENTBREMSSTRAHLUNGCEBAFCLASPHOTONPHOTOPRODUCTIONPIONREACTION GAMMA-P

Last updated on 2025-01-04 at 23:06