Radiative decays of scalar mesons σ(600), f 0(980) and a 0(980) in the local Nambu-Jona-Lasinio model

The two-photon decay widths of scalar mesons σ(600), f 0(980) and a 0(980) as well a 0 → ju(ω)γ and f 0 → ju(ω)γ 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/N c-approximation where N c is the number of colors) are taken into account. The values of these contributions, as we show, are of the same order of magnitude. For the f 0 decay the K-loop contribution plays the dominant role. The results for two-gamma decays are in satisfactory agreement with modern experimental data. The predictions for a 0 → ju(ω)γ and f 0 → ju(ω)γ widths are given.