One-loop corrections to single spin asymmetries at twist-3 in Drell-Yan processes

Abstract

We study single spin asymmetries at one-loop accuracy in Drell-Yan processes in which one of the initial hadrons is transversely polarized. The spin-dependent part of differential cross sections can be factorized with various hadronic matrix elements of twist-2 and twist-3 operators. These operators can be of even and odd chirality. In this work, the studied observables of asymmetries are differential cross sections with different weights. These weights are selected so that the observables are spin dependent and their virtual corrections are completely determined by the quark form factor. In the calculations of one-loop corrections we meet collinear divergences in the contributions involving chirality-odd and chirality-even operators. We find that all of the divergences can be correctly subtracted. Therefore, our results give an explicit example of QCD factorization at one loop with twist-3 operators, especially QCD factorization with chirality-odd twist-3 operators.