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Using Jet Asymmetries to access the Gluon Helicity Distribution of the Proton at STAR

Renee Fatemi
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Abstract

We present the first inclusive jet longitudinal double spin asymmetry A_LL and differential cross-section measurement from STAR. This analysis reflects ~1 pb^-1 of polarized pp data taken at sqrt{s}=200 GeV with beam polarizations of 30-45% in years 2003 and 2004. Agreement between the measured differential cross-section and next-to-leading order (NLO) calculations validate the interpretation of the asymmetry results within the framework of perturbative Quantum Chromodynamics (pQCD). A_LL is compared to NLO pQCD calculations, which incorporate several possible gluon helicity distributions, and is shown to disfavor the maximum gluon scenario.

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Renee Fatemi. 2006-06-02. Using Jet Asymmetries to access the Gluon Helicity Distribution of the Proton at STAR. https://arxiv.org/abs/nucl-ex/0606007

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