Scalar σ meson effects in ρ and ω decays

The complementarity between Chiral Perturbation Theory and the Linear Sigma Model in the scalar channel is exploited to study π0 π0 production in ρ and ω radiative decays, where the effects of a low mass scalar resonance σ (500) should manifest. The recently reported data on ρ → π0 π0 y seem to require the contribution of a low mass and moderately narrow σ (500). The properties of this controversial state could be fixed by improving the accuracy of these measurements. Data on ω → π0 π0 y can also be accommodated in the framework, but are much less sensitive to the σ (500) properties