Meson Electro-Magnetic Form Factors in an Extended Nambu--Jona-Lasinio model including Heavy Quark Flavors

TL;DR

This paper extends the Nambu--Jona-Lasinio model to include heavy quark flavors and calculates meson electromagnetic form factors, showing good agreement with experimental data for light mesons and providing predictions for heavy mesons.

Contribution

It introduces an extended NJL model incorporating heavy quark flavors and computes meson form factors with vector-meson dominance effects, advancing theoretical understanding of meson structure.

Findings

Form factors and electric radii of π+ and K+ match experimental data.

Magnetic moments of ρ+ and K*+ are consistent with other theories.

Provides form factor predictions for light-heavy mesons.

Abstract

Based on an extended NJL model including heavy quark flavors, we calculate the form factors of pseudo-scalar and vector mesons. After take into account of the vector-meson-dominance effect which introduce a form factor correction to the quark vector coupling vertices, the form factors and electric radii of $\pi^+$ and $K^+$ of pseudo-scalar meson in light flavor sector fit the experimental data well. Also the magnetic moments of light vector meson $\rho^+$ and $K^{*+}$ are comparable with other theoretical calculation. The form factors in light-heavy flavor sector are presented to confront with future experiments or theoretical calculations.