Rho meson form factors in a confining Nambu--Jona-Lasinio model

TL;DR

This paper calculates the electromagnetic form factors of the rho+ meson using a confining Nambu--Jona-Lasinio model, comparing results with lattice QCD and previous models, showing good qualitative agreement.

Contribution

It introduces a confining NJL model with proper-time regularization to compute rho meson form factors and compares these with lattice QCD results, highlighting areas of agreement and discrepancy.

Findings

Qualitative agreement with lattice QCD for most form factors.

Discrepancy in quadrupole moment possibly due to lattice symmetry issues.

Provides a new approach to modeling rho meson electromagnetic properties.

Abstract

Elastic electromagnetic form factors for the $\rho^+$ meson are calculated in a Nambu--Jona-Lasinio model which incorporates quark confinement through the use of the proper-time regularization scheme. A comparison is made with recent lattice QCD results and previous quark model calculations for static quantities and the Sachs form factors. The results are qualitatively in good agreement with the lattice QCD calculations, with the exception of the quadrupole moment and corresponding form factor, which may be related to a lack of spherical symmetry on the lattice.