Unpolarized generalized parton distributions of light and heavy vector mesons

TL;DR

This paper investigates the unpolarized generalized parton distributions (GPDs) of light and heavy vector mesons using a modified light front overlap approach, providing insights into their internal structure and form factors.

Contribution

It introduces an ansatz with zero mode contributions and employs DS-BSEs derived light front wave functions to study GPDs of vector mesons.

Findings

Light front mass radius of ρ meson is 0.30 fm.

Predicted mass radii for J/ψ and Υ are 0.151 fm and 0.089 fm.

GPDs and form factors are computed and analyzed.

Abstract

We study the leading-twist unpolarized generalized parton distributions (GPDs) of light and heavy vector mesons, i.e., the $\rho$, $J/\psi$ and $\Upsilon$, at zero skewness. An ansatz incorporating the zero mode contribution is introduced to modify the light front overlap representation of GPDs. The leading Fock-state light front wave functions (LF-LFWFs) of vector mesons from DS-BSEs approach are then employed to study the meson GPDs. The light front spatial distribution of valence quarks within vector mesons is then studied with the impact parameter dependent GPD (IPD GPD). We also investigate the electromagnetic and gravitational form factors, which are the first and second Mellin moments of the GPDs. The light-cone mass radius of $\rho$ is determined to be 0.30 fm, close to a recent NJL model prediction 0.32fm. For $J/\psi$ and $\Upsilon$, they are predicted to be 0.151fm and 0.089 fm respectively.