MESON-EXCHANGE MODEL FOR PI-N SCATTERINGS AND PION-PHOTOPRODUCTION REACTIONS

A meson-exchange model, based on a three-dimensional reduction of Bethe-Salpeter equation, for pi-N interaction and pion photoproduction reactions is presented. The model is able to describe pi-N phase shifts and pion photoproductions from nucleon at low energy. Rescattering effects are found to play important role in gamma-pi reaction in most multipole channels. The constructed meson-exchange potential is used to evaluate rescattering effects in the dipole amplitude E0+ of pi-0 photoproduction from proton near threshold. The results are close to the most recent Mainz data.