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

TL;DR

This paper calculates the two-photon decay widths of scalar mesons (600), f_0(980), and a_0(980) using the Nambu-Jona-Lasinio model, considering quark and meson loop contributions, and finds results consistent with experimental data.

Contribution

It provides a detailed calculation of scalar meson -decays including meson loop effects within the NJL model, highlighting the dominant K-loop contribution for f_0 decay.

Findings

Decay widths are of the same order for quark and meson loops.

K-loop contribution dominates in f_0 decay.

Results agree with experimental measurements.

Abstract

The two-photon decay widths of scalar mesons \sigma(600), f_0(980) and a_0(980) are calculated in framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock approximation) and the meson loops (next 1/N_c-approximation where N_c 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 are in satisfactory agreement with modern experimental data.