New Measurements of the Proton Double-Spin Asymmetries A_1 and A_2 In and Above the Resonance Region
- College of William and Mary, Williamsburg, VA (United States)
The CLAS EG1b experiment in Hall-B at Jefferson Laboratory utilized a polarized electron beam at various (1.6, 2.5, 4.2, 5.7 GeV) energies and polarized frozen NH3 and ND3 targets to measure double-polarization asymmetries of inclusive electron-nucleon scattering. The proton asymmetry A1 has been extracted from the double-spin asymmetry (at 0.15 GeV2 < Q2 < 2.0 GeV2). Newly analyzed data at 2.5 and 4.2 GeV allows a more complete integration in x of the g1 structure function than provided by previous analysis, reducing models dependency in the calculation of Gamma_1, the first moment of g1. A linear regression of the asymmetries in terms of eta= epsilon sqrt Q2/(E - epsilon E') also provides a rudimentary measurement of A2 in the region of kinematic overlap for the varying beam energies.
- Research Organization:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1964114
- Report Number(s):
- JLAB-PHY-07-965; DOE/OR/23177-5918
- Country of Publication:
- United States
- Language:
- English
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