The effect of isospin violation on scalar meson production

TL;DR

This paper studies how isospin violation affects the mixing of light scalar mesons a0(980) and f0(980) using a unitarized chiral approach, providing new predictions for reaction cross sections.

Contribution

It introduces a framework incorporating isospin violation into meson-meson dynamics, describing scalar meson mixing consistent with chiral symmetry and unitarity.

Findings

Predicted cross sections for J/Psi to phi K+K- and K0  K0^0 channels with isospin violation.

Provided first theoretical estimates of isospin-violating effects in scalar meson production.

Demonstrated meson resonances as dynamically generated states rather than quark-antiquark pairs.

Abstract

We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass difference and electromagnetism. In this approach both resonances are generated through meson-meson dynamics. Our results provide a description of the mixing phenomenon within a framework consistent with chiral symmetry and unitarity, where these resonances are not predominantly quark-antiquark states. We discuss in detail the reactions J/Psi to phi S, where S denotes a suitable pair of pseudo--scalar mesons in the scalar channel, namely pi0 eta, K+K-, and K0 \bar K^0. In this work predictions for the cross section in the kaon channels are given for the first time with isospin violating effects included.