Transverse spin asymmetries for W-production in proton–proton collisions

摘要

We study parity-even and parity-odd polarization observables for the processpp→l±X, where the lepton comes from the decay of aW-boson. By using the collinear twist-3 factorization approach, we consider the case when one proton is transversely polarized, while the other is either unpolarized or longitudinally polarized. These observables give access to two particular quark–gluon–quark correlation functions, which have a direct relation to transverse momentum dependent parton distributions. We present numerical estimates for RHIC kinematics. Measuring, for instance, the parity-even transverse single spin correlation would provide a crucial test of our current understanding of single spin asymmetries in the framework of QCD.