Scalar and vector meson exchange in V->P0P0gamma decays

Abstract

The scalar contributions to the radiative decays of light vector mesons into a pair of neutral pseudoscalars, $V\to P^0{P}^0\gamma$, are studied within the framework of the Linear Sigma Model. This model has the advantage of incorporating not only the scalar resonances in an explicit way but also the constraints required by chiral symmetry. The experimental data on $\varphi \to {\pi }^0{\pi }^0\gamma$, $\varphi \to {\pi }^0\eta \gamma$, $\rho \to {\pi }^0{\pi }^0\gamma$ and $\omega \to {\pi }^0{\pi }^0\gamma$ are satisfactorily accommodated in our framework. Theoretical predictions for $\varphi \to K^0{\bar{K}}^0\gamma$, $\rho \to {\pi }^0\eta \gamma$, $\omega \to {\pi }^0\eta \gamma$ and the ratio $\varphi \to f_0\gamma /a_0\gamma$ are also given.

Comments: 42 pages, 11 figures. A new paragraph explaining the seminal contribution of Ref. [19] is added