Charge asymmetry and radiative ϕ decays

The study of radiative ϕ decays into scalar mesons, with subsequent decay into ππγ, constitutes an important topic at the electron-positron collider DAPHNE. The interference of the respective amplitude with the one for π+π−γ production, where the photon originates from initial state radiation, will allow for unambiguous tests of models for the ϕ→γf0(→ππ) amplitude. The forward-backward asymmetry of charged pions, which is a clear signal of such an interference, amounts up to 30% and is at the same time quite sensitive to the details of the various amplitudes. The results for several characteristic cases are presented and their implementation into the Monte Carlo generator PHOKHARA is described.