Double Transverse-Spin Asymmetries for Small-QT Drell-Yan Pair Production in pp-bar Collisions

We discuss the double-spin asymmetries in transversely polarized Drell-Yan process, calculating all-order gluon resummation corrections up to the next-to-leading logarithmic accuracy. This resummation is relevant when the transverse-momentum QT of the produced lepton pair is small, and reproduces the (fixed-order) next-to-leading QCD corrections upon integrating over QT. The resummation corrections in pp-bar-collision behave differently compared with pp-collision cases, and are small at the kinematics in the proposed GSI experiments. This fact allows us to predict large value of the double-spin asymmetries at GSI, using recent empirical information on the transversity.