  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 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 with twist-3 operators,
especially, QCD factorization with chirality-odd twist-3 operators.
