Test of FSR in the process e+e−→π+π−γ at DAΦNE and extraction of the pion form factor at threshold

Abstract Effects due to non-pointlike behavior of pions in the process e + e − → π + π − γ can arise for hard photons in the final state. By means of a Monte Carlo event generator, which also includes the contribution of the direct decay ϕ → π + π − γ , we estimate these effects in the framework of resonance perturbation theory. We consider angular cuts used in the KLOE analysis of the pion form factor at threshold. A method to reveal the effects of non-pointlike behavior of pions in a model-independent way is proposed.