QCD corrections to longitudinal spin asymmetries in W±-boson production at RHIC

The polarized antiquark distributions in the proton can be measured by studying spin asymmetries in vector boson production in longitudinally polarized proton-proton collisions. The STAR and PHENIX experiments at BNL RHIC have reported first observations of single spin asymmetries in W± production most recently. We compute the QCD corrections to single and double spin asymmetries, taking account of the leptonic decay of the W± boson and of restrictions on the kinematical acceptance of the detectors. The QCD corrections have only a small impact on the asymmetries, such that a reliable extraction of the polarized antiquark distributions can be envisaged once more precise measurements are made.