The Dilepton Q_T Spectrum in Transversely Polarized Drell-Yan Process in QCD

We discuss the transverse momentum Q_T distribution of Drell-Yan pair, produced in collisions of transversely polarized protons. We calculate the transversely polarized Drell-Yan cross section up to order \alpha_s in the dimensional regularization scheme, which gives QCD prediction at large Q_T. For small Q_T region, we include all-orders resummation of large logarithms due to emission of soft gluons up to next-to-leading logarithmic accuracy. At intermediate Q_T region, the resummation formula is matched with the fixed-order \alpha_s perturbative results in a systematic way, so that we derive the cross section with uniform accuracy over the entire range of Q_T.