Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton
Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θPcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- Contributing Organization:
- Jefferson Lab Hall C Collaboration
- Grant/Contract Number:
- AC05-84ER40150
- OSTI ID:
- 1226145
- Alternate ID(s):
- OSTI ID: 1223139
- Report Number(s):
- JLAB-PHY-15-2059; DOE/OR/23177-3372; arXiv:1506.04045; PRLTAO
- Journal Information:
- Physical Review Letters, Vol. 115, Issue 15; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
The GPD H̃ and spin correlations in wide-angle Compton scattering
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journal | June 2017 |
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