Differential Cross Section and Photon-Beam Asymmetry for the gamma(->)p -> Pi(-)Delta(+ +) (1232) Reaction at Forward Pi(-) Angles for E-gamma=1.5-2.95 GeV
- Authors
- Kohri, H.; Shiu, S. H.; Chang, W. C.; Yanai, Y.; Ahn, D. S.; Ahn, J. K.; Chen, J. Y.; Date, S.; Ejiri, H.; Fujimura, H.; Fujiwara, M.; Fukui, S.; Gohn, W.; Hicks, K.; Hosaka, A.; Hotta, T.; Hwang, S. H.; Imai, K.; Ishikawa, T.; Joo, K.; Kato, Y.; Kon, Y.; Lee, H. S.; Maeda, Y.; Mibe, T.; Miyabe, M.; Morino, Y.; Muramatsu, N.; Nakano, T.; Nakatsugawa, Y.; Nam, S., I; Niiyama, M.; Noumi, H.; Ohashi, Y.; Ohta, T.; Oka, M.; Parker, J. D.; Rangacharyulu, C.; Ryu, S. Y.; Sawada, T.; Shimizu, H.; Strokovsky, E. A.; Sugaya, Y.; Sumihama, M.; Tsunemi, T.; Uchida, M.; Ungaro, M.; Wang, S. Y.; Yosoi, M.
- Issue Date
- 18-5월-2018
- Publisher
- AMER PHYSICAL SOC
- Citation
- PHYSICAL REVIEW LETTERS, v.120, no.20
- Indexed
- SCIE
SCOPUS
- Journal Title
- PHYSICAL REVIEW LETTERS
- Volume
- 120
- Number
- 20
- URI
- https://scholar.korea.ac.kr/handle/2021.sw.korea/75511
- DOI
- 10.1103/PhysRevLett.120.202004
- ISSN
- 0031-9007
- Abstract
- Differential cross sections and photon-beam asymmetries for the gamma(->)p -> Pi(-)Delta(++)(1232) reaction have been measured for 0.7 < cos Theta(c.m.)(Pi) < 1 and E-gamma= 1.5-2.95 GeV at SPring-8/LEPS. The first-ever high statistics cross-section data are obtained in this kinematical region, and the asymmetry data for 1.5 < E-gamma(GeV) < 2.8 are obtained for the first time. This reaction has a unique feature for studying the production mechanisms of a pure uu quark pair in the final state from the proton. Although there is no distinct peak structure in the cross sections, a non-negligible excess over the theoretical predictions is observed at E-gamma= 1.5-1.8 GeV. The asymmetries are found to be negative in most of the present kinematical regions, suggesting the dominance of n exchange in the t channel. The negative asymmetries at forward meson production angles are different from the asymmetries previously measured for the photoproduction reactions producing a dd(-) or an ss quark pair in the final state. Advanced theoretical models introducing nucleon resonances and additional unnatural-parity exchanges are needed to reproduce the present data.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Science > Department of Physics > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.