Pseudoscalar Meson Parton Distributions Within Gauge-Invariant Nonlocal Chiral Quark Model

TL;DR

This paper models the gluon and valence-quark distributions in pions and kaons using a gauge-invariant nonlocal chiral quark model, showing good agreement with recent lattice QCD and experimental data.

Contribution

It introduces a gauge-invariant nonlocal chiral quark model to compute meson parton distributions, incorporating momentum dependence and QCD evolution.

Findings

Pion gluon distributions agree with lattice QCD at 2 GeV.

Valence-quark distribution matches experimental reanalysis at 5.2 GeV.

Kaon gluon distributions are consistent with recent lattice results.

Abstract

In this paper, I investigate the gluon distributions for the kaon and pion, as well as the improvement of the valence-quark distributions, in the framework of the gauge-invariant nonlocal chiral quark model (NL$\chi$QM), where the momentum dependence is taken into account. I then compute the gluon distributions for the kaon and pion that are dynamically generated from the splitting functions in the DGLAP QCD evolution. In a comparison with the recent lattice QCD and JAM global analysis results, it is found that the results for the pion gluon distributions at $Q =$ 2 GeV, which is set based on the lattice QCD, have a good agreement with the recent lattice QCD data; this is followed up with the up valence-quark distribution of the pion results at $Q =$ 5.2 GeV in comparison with the reanalysis experimental data. The prediction for the kaon gluon distributions at $Q = 2$ GeV is consistent with the recent lattice QCD calculation.