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−→h1h2X 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.