Longitudinal Double Spin Asymmetry and Cross Section for Direct Photon Production Measured at Mid-rapidity in Polarized {radical}(s) = 200 GeV pp Collisions at PHENIX

Journal Article · Tue Aug 04 00:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3215642· OSTI ID:21316906

Bennett, Robert ^[1]

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1. State University of New York at Stony Brook, Department of Physics and Astronomy, Stony Brook NY 11790 (United States)

Direct photon production in pp collisions at RHIC is one of the important channels PHENIX will employ to determine the polarized gluon distribution {delta}G. The direct photon A{sub LL} is linear in {delta}G, therefore sensitive to its sign and magnitude. To establish the applicability of perturbative Quantum Chromodynamics (pQCD) to this process, we present a comparison of the direct photon unpolarized cross section, with next-to-leading order pQCD calculations. We then evaluate the double helicity spin asymmetries, A{sub LL}, from these data and compare with theoretical models. We present results and the current status the analysis of 2005 and 2006 data sets.

• OSTI ID: 21316906
• Journal Information: AIP Conference Proceedings, Vol. 1149, Issue 1; Conference: 18. international spin physics symposium, Charlottesville, VA (United States), 6-11 Oct 2008; Other Information: DOI: 10.1063/1.3215642; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BROOKHAVEN RHIC
COMPARATIVE EVALUATIONS
CROSS SECTIONS
GEV RANGE
GLUONS
HELICITY
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
PARTICLE PRODUCTION
PARTICLE RAPIDITY
PHOTONS
POLARIZATION
PROTON-PROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
SPIN