Transversity and Collins Fragmentation Functions: Towards a New Global Analysis

Abstract

A new, preliminary global analysis of the experimental data on azimuthal asymmetries in SIDIS from HERMES and COMPASS collaborations, and in e+e- --> h_1 h_2 X processes from the BELLE collaboration, is performed. The new data allow for a more precise determination of the Collins fragmentation function and of the transversity distribution function for $u$ and $d$ quarks, in comparison with the results of our previous analysis. Estimates for the single spin asymmetry A_UT^{\sin(ϕ_h + ϕ_S)} at JLab and COMPASS, operating on a transversely polarized proton target, are presented.

4 pages, 4 figures. To appear in the proceedings of the XVI International Workshop on Deep Inelastic Scattering and Related Subjects, DIS 2008, London, U.K., 7-11 April, 2008