Comparative analysis of the transversities and the longitudinally polarized distribution functions of the nucleon

A first empirical extraction of the transversity distributions for the u- and d-quarks has been done by Anselmino et al. based on the combined global analysis of the measured azimuthal asymmetries in semi-inclusive deep inelastic scatterings and those in e(+)e- ->-> h(1)h(2)X processes. although with large uncertainties, the determined transversity distributions already appear to reveal a remarkable qualitative difference with the corresponding longitudinally polarized distributions. We point out that this difference contains very important information on internal spin structure of the nucleon. (C) 2007 Elsevier B.V.. All rights reserved.