2γ-decays of scalar mesons (σ(600), f0(980) and a0(980)) in the Nambu-Jona-Lasinio model

Abstract

The two-photon decay widths of scalar mesons σ(600), f0(980) and a0(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/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 f0 decay the K-loop contribution turns out to play the dominant role. The results are in satisfactory agreement with modern experimental data.