Using Jet Asymmetries to access the Gluon Helicity Distribution of the   Proton at STAR
  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. 
Renee Fatemi (for the STAR Collaboration)