Chiral loops and VMD in the V->PPgamma decays

Abstract

We evaluate radiative decays of $\rho$ and $\omega$ going to two neutral mesons, $\pi^{0} \pi^{0}$ and $\pi^{0} \eta$. We use the sequential vector decay mechanisms in addition to chiral loops and $\rho$-$\omega$ mixing. The chiral loops are obtained using elements of $U\chi PT$ successfully applied in the study of meson-meson interactions up to 1.2 GeV. The chiral loops are found very important in the case of the $\rho \to \pi^{0} \pi^{0} \gamma$ decay and small in the other cases. A good agreement with present measurements of $\rho \to \pi^{0} \pi^{0} \gamma$ and $\omega \to \pi^{0} \pi^{0}\gamma$ is obtained and predictions are made for the other decays where the rates obtained are rather small.