A quark model analysis of the transversity distribution: Next to leading order evolution

The feasibility of measuring chiral-odd parton distribution functions in polarized Drell-Yan and semi-inclusive experiments has renewed theoretical interest in their study. Not long ago we presented an analysis of the transversity distribution functions using models of hadron structure and Leading Order evolution. In the meantime Next to Leading Order evolution equations for $h_1$ are also available. We here present a comparison between the LO and the NLO results which confirms our previous conclusions.