Phenomenological analysis of photon-proton elastic scattering

Summary  Recent experimental data on Compton scattering by the proton at energies above 300 MeV suggest an extension of previous phenomenological calculations. The present model takes into account the Thompson and magnetic moment scattering, the electric dipole scattering from the virtual charged pion current, and the « Low diagram » dependent on the π0 mean life. The resulting differential cross-section is in qualitative agreement with the available data. The polarization of the recoil proton and the dependence on incident photon polarization are also calculated. Above 500 MeV the cross-sections for unpolarized and polarized photons and the recoil proton polarization are all quite sensitive to the π0 mean life.