Phenomenology of single transverse spin asymmetries

Abstract

A unified and consistent phenomenological approach to single transverse spin asymmetries in the framework of perturbative QCD, with the inclusion of a new class of spin and k_T dependent distribution and fragmentation functions, is presented. As an example, results on A_N(p(pol) p --> pion X) and P_Lambda(p p -->Lambda(pol) X) are shown.

Comments: 8 pages, 3 figures, uses epsfig.sty. Talk delivered by U. D'Alesio at the ``VIII Convegno su Problemi di Fisica Nucleare Teorica'', October 18-20, 2000, Cortona, Italy