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

TL;DR

This paper discusses the first empirical extraction of transversity distributions for u- and d-quarks, highlighting their qualitative differences from longitudinally polarized distributions and emphasizing their significance for understanding nucleon spin structure.

Contribution

It presents the initial empirical extraction of transversity distributions and compares them with longitudinally polarized distributions, revealing important insights into nucleon spin structure.

Findings

Transversity distributions differ qualitatively from longitudinally polarized distributions.

Empirical extraction of transversity distributions has been achieved.

Differences in distributions provide insights into nucleon internal spin structure.

Abstract

A first empirical extraction of the transversity distributions for the $u$- and $d$-quarks has been done by Anselmino {\it et al.} based on the combined global analysis of the measured azimuthal asymmetries in semi-inclusive deep inelastic scatterings and those in $e^+ e^- \to h_1 h_2 X$ 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.