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Title: Polarization components in π0 photoproduction at photon energies up to 5.6 GeV

We present new data for the polarization observables of the final state proton in the 1H(→ γ, → p)π0 reaction. These data can be used to test predictions based on hadron helicity conservation (HHC) and perturbative QCD (pQCD). These data have both small statistical and systematic uncertainties, and were obtained with beam energies between 1.8 and 5.6 GeV and for π0 scattering angles larger than 75{sup o} in center-of-mass (c.m.) frame. The data extend the polarization measurements data base for neutral pion photoproduction up to Eγ = 5.6 GeV. The results show non-zero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and π0 scattering angle in the center-of-mass frame. This indicates that HHC does not hold and that the pQCD limit is still not reached in the energy regime of this experiment.
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Publication Date:
OSTI Identifier:
1049533
Report Number(s):
JLAB-PHY-12-1618; DOE/OR/23177-2307
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US1204462
Grant/Contract Number:
AC05-06OR23177
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 108; Journal Issue: 22; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE SC Office of High Energy Physics (SC-25)
Contributing Orgs:
GEp-III and GEp2γ Collaborations
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; HADRONS; HELICITY; PHOTONS; PHOTOPRODUCTION; PIONS; POLARIZATION; PROTONS; QUANTUM CHROMODYNAMICS; RESONANCE; SCATTERING