The e+ e- -> P1 P2 gamma processes close to the Phi peak: toward a model-independent analysis

Abstract

We discuss the general decomposition and possible general parameterizations of the processes $e^+ e^- \to γ^* \to P_1 P_2 γ$, where $P_1 P_2=π^0 π^0$, $π^0η$, or $π^+π^-$, for $\sqrt{s}\approx M_Φ$. Particular attention is devoted to the amplitude where the two pseudoscalar mesons are in a $J^{CP}= 0^{++}$ state, where we propose a general parameterization which should help to shed light on the nature of light scalar mesons.