Unified study of scalar, vector and tensor two-meson form factors in $U(3)$ resonance chiral theory

TL;DR

This paper systematically studies scalar, vector, and tensor two-meson form factors within $U(3)$ resonance chiral theory, combining perturbative calculations with unitarization to reveal resonance structures.

Contribution

It provides a comprehensive calculation of two-meson form factors, including unitarization and resonance effects, extending previous scattering results.

Findings

Distinct resonance structures observed across different form factor types.

Constructed unitarized form factors incorporating meson-meson interactions.

Predicted form factors using parameters from previous scattering studies.

Abstract

We perform a systematic study of two-meson form factors of the scalar, vector, and anti-symmetric tensor types within the framework of the $U(3)$ resonance chiral theory. The complete perturbative form factors in both the strangeness-conserving and strangeness-changing channels are calculated by incorporating one-loop light-flavor pseudoscalar meson contributions and tree-level resonance exchanges. With these newly calculated chiral results, we construct the corresponding unitarized form factors by incorporating meson-meson final-state interactions. The parameter values obtained in previous meson-meson scattering studies are then exploited to predict the corresponding form factors. Different types of form factors are found to exhibit rather distinct resonance structures across channels.