Fragmentation and quark distribution functions for the pion and kaon with explicit flavor-SU(3)-symmetry breaking

TL;DR

This paper uses a nonlocal chiral-quark model to analyze pion and kaon fragmentation and quark-distribution functions, explicitly considering flavor-SU(3) symmetry breaking, and compares results with empirical data.

Contribution

It introduces a detailed calculation of fragmentation and distribution functions incorporating explicit flavor symmetry breaking within a nonlocal chiral-quark framework.

Findings

Results agree well with experimental data.

Ratios of valence quark-distribution functions are consistent with other models.

Higher Q^2 evolution matches empirical observations.

Abstract

We investigate the unpolarized pion and kaon fragmentation functions, employing the nonlocal chiral-quark model, which manifests the nonlocal interactions between the quarks and pseudoscalar mesons, considering the explicit flavor-SU(3)-symmetry breaking in terms of the current-quark masses. Moreover, we study the quark-distribution functions, derived from the fragmentation ones with the Drell-Yan-Levi relation. Numerical results are evaluated to higher Q^2 by the DGLAP evolution and compared with the empirical data. The ratios between the relevant valance quark-distribution functions are also discussed. It turns out that the present results are in relatively good agreement with available data and other theoretical estimations.