Transversity and Mass Singularities in Dimensional Regularization

The proton's transversity distribution will be measured at BNL's Relativistic Heavy Ion Collider in upcoming experiments using the transverse Drell-Yan process. Understanding the one-loop corrections is therefore important. Here, the collinear structure in transverse Drell-Yan is investigated in detail using dimensional regularization and the correct behaviour is found, although the mechanism is non-trivial. The resulting n-dimensional transversity splitting function (and consequently the one-loop transversity distribution and its two-loop evolution) is found to be the same in both the anticommuting-gamma_5 scheme and the HVBM scheme. Alternative schemes are considered.