Radiative decays of scalar mesons \sigma(600), f_0(980) and a_0(980) in the local Nambu-Jona-Lasinio model

TL;DR

This paper calculates the two-photon decay widths of scalar mesons 00, f_0(980), and a_0(980) using the local Nambu-Jona-Lasinio model, considering quark and meson loop contributions, and compares results with experimental data.

Contribution

It provides a detailed calculation of scalar meson radiative decays within the NJL model, including both quark and meson loop effects, and offers new predictions for specific decay widths.

Findings

Quark and meson loops contribute similarly to decay widths.

K-loop dominates the f_0 decay process.

Results agree with current experimental data.

Abstract

The two-photon decay widths of scalar mesons \sigma(600), f_0(980) and a_0(980) as well a_0 -> \rho(\omega)\gamma and f_0 -> \rho(\omega)\gamma are calculated in the framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock approximation) and the meson loops (next 1/Nc -approximation where Nc is the number of colors) are taken into account. These contributions, as we show, are the values of the same order of magnitude. For the f_0 decay the K-loop contribution turns out to play the dominant role. The results for two-gamma decays are in satisfactory agreement with modern experimental data. The predictions for a_0 -> \rho(\omega)\gamma and f_0 -> \rho(\omega)\gamma widths are given.