Self-consistent covariant description of vector meson decay constants and chirality-even quark-antiquark distribution amplitudes up to twist-3 in the light-front quark model

TL;DR

This paper develops a covariant light-front quark model to analyze vector meson decay constants and quark-antiquark distribution amplitudes up to twist-3, addressing the zero-mode issue and ensuring consistency with QCD chiral symmetry.

Contribution

It introduces a self-consistent covariant framework for vector meson decay constants and distribution amplitudes up to twist-3 within the light-front quark model, extending previous models.

Findings

Resolved the zero-mode issue in decay constant calculations.

Provided a covariant description of twist-2 and twist-3 distribution amplitudes.

Ensured compatibility with QCD vacuum dynamics and chiral symmetry.

Abstract

Although the meson decay amplitude described by a two-point function may be regarded as one of the simplest possible physical observable, it is interesting that this apparently simple amplitude bears abundant fundamental informations on QCD vacuum dynamics and chiral symmetry. The light-front zero-mode issue of the vector meson decay constant $f_V$ is in this respect highly non-trivial and deserves careful analyses. We discuss the zero-mode issue in the light-front quark model (LFQM) prediction of $f_V$ from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. We extend the exactly solvable manifestly covariant Bethe-Salpeter model calculation to the more phenomenologically accessible realistic LFQM and present a self-consistent covariant description of $f_V$ analyzing the twist-2 and twist-3 quark-antiquark distribution amplitudes with even chirality.