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Title: Target and beam-target spin asymmetries in exclusive π + and π electroproduction with 1.6- to 5.7-GeV electrons

Here, beam-target double-spin asymmetries and target single-spin asymmetries in exclusive π + and quasiexclusive π electroproduction were obtained from scattering of 1.6- to 5.7-GeV longitudinally polarized electrons from longitudinally polarized protons (for π +) and deuterons (for π ) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is 1.1 < W < 2.6 GeV and 0.05 < Q 2 < 5GeV 2, with good angular coverage in the forward hemisphere. The asymmetry results were divided into approximately 40 000 kinematic bins for π + from free protons and 15 000 bins for π production from bound nucleons in the deuteron. The present results are found to be in reasonable agreement with fits to previous world data for W < 1.7 GeV and Q 2 < 0.5GeV 2, with discrepancies increasing at higher values of Q 2, especially for W > 1.5 GeV. Very large target-spin asymmetries are observed for W > 1.6 GeV. When combined with cross-section measurements, the present results can provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q 2, for resonances with masses as high as 2.3 GeV.
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Publication Date:
Report Number(s):
JLAB-PHY-16-2294; DOE/OR/23177-3875; arXiv:1604.04350
Journal ID: ISSN 2469-9985; PRVCAN; TRN: US1700169
Grant/Contract Number:
AC05-06OR23177; SC0016583
Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 94; Journal Issue: 5; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); George Washington Univ., Washington, DC (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF; Scottish Universities Physics Alliance (SUPA); United Kingdom’s Science and Technology Facilities Council; National Research Foundation of Korea (NRF); Italian Instituto Nazionale di Fisica Nucleare; French Centre National de la Recherche Scientifique; French Commissariat `a l’Energie Atomique; German Research Foundation (DFG)
Contributing Orgs:
CLAS Collaboration
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; pion electroproduction
OSTI Identifier:
1330792
Alternate Identifier(s):
OSTI ID: 1330606; OSTI ID: 1439591