Kaon quark distribution functions in the chiral constituent quark model

TL;DR

This study models the valence quark distributions in the $K^+$ meson using the chiral constituent quark model, incorporating meson cloud effects and QCD evolution, aligning well with experimental data and showing reduced flavor symmetry breaking.

Contribution

It introduces a method to determine dressed valence quark distributions in the $K^+$ meson within the chiral constituent quark model, considering meson cloud effects and QCD evolution, with improved symmetry breaking insights.

Findings

Distribution functions agree with experimental data.

Meson cloud effects significantly modify bare distributions.

Reduced $SU(3)$ flavor symmetry breaking observed.

Abstract

We investigate the valence $u$ and $\bar{s}$ quark distribution functions of the $K^+$ meson, $v^{K(u)}(x,Q^2)$ and $v^{K(\bar{s})}(x,Q^2)$, in the framework of the chiral constituent quark model. We judiciously choose the bare distributions at the initial scale to generate the dressed distributions at the higher scale, considering the meson cloud effects and the QCD evolution, which agree with the phenomenologically satisfactory valence quark distribution of the pion and the experimental data of the ratio $v^{K(u)}(x,Q^2)/v^{\pi (u)}(x,Q^2)$. We show how the meson cloud effects affect the bare distribution functions in detail. We find that a smaller $SU(3)$ flavor symmetry breaking effect is observed, compared with results of the preceding studies based on other approaches.