Vector-meson-dominance model for radiative decays involving light scalar mesons

We study a vector-dominance model which predicts quite a large number of currently interesting decay amplitudes of the types S-->gammagamma, V-->Sgamma, and S-->Vgamma, where S and V denote scalar and vector mesons, in terms of three parameters. As an application, the model makes it easy to study in detail a recent proposal to boost the ratio Gamma(phi-->f(0)gamma)/Gamma(phi-->a(0)(0)gamma) by including the isospin violating a(0)(0)-f(0) mixing. However, we find that this effect is actually small in our model.