Radiative vector meson decays in the NJL model revisited

Full text follows: The analysis of vector and axial-vector meson physics represents a nontrivial task from the theoretical point of view. This is basically due to the characteristic energy scales at which these particles manifest, namely an intermediate range between low energy hadron physics and the high energy region where QCD can be treated perturbatively. In order to deal with the subject, one possible approach is to derive the effective interactions from QCD-inspired fermionic schemes. In this work we follow this line, revisiting some aspects of spin 1 meson physics in the framework of the Nambu and Jona-Lasinio (NJL) model. After bosonization, we obtain an effective Lagrangian to account for vector and axial-vector meson interactions, in the limit of explicit breakdown of chiral SU(3). This leads to some relations between vector meson masses and decay constants that can be written in terms of symmetry breaking parameters. Then we concentrate on radiative decays of vector mesons, which proceed through the U(1)A anomaly. The predictions arising from the model for the corresponding branching ratios are discussed in comparison with the available experimental information and the results obtained from previous approaches. (author)