Tests of the final-state radiation model at DAFNE near π + π - threshold
INFN Laboratori Nazionale di Frascati, 00044, Frascati (RM), Italy
2 NSC “Kharkov Institute for Physics and Technology”, Institute for Theoretical Physics, 61108, Kharkov, Ukraine
Accepted: 15 November 2006
Published online: 6 March 2007
Effects due to the non-pointlike behaviour 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 the 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 the non-pointlike behaviour of pions in a model-independent way is proposed.
PACS: 13.25.Jx Decays of other mesons – / 12.39.Fe Chiral Lagrangians – / 13.40.Gp Electromagnetic form factors –
© Società Italiana di Fisica and Springer-Verlag, 2007