Meson NucleonS scattering and crossing theorem

Abstract

It is noticed that the low energyS wave calculations of meson nucleon scattering cannot be very satisfactory if they do not obey the « crossing theorem ». It may be interesting to modify the iteration treatments in order to satisfy the symmetry requirements. For this purpose the series of scattering processes considered is completed by a new series in which the initial meson and the final meson are exchanged. In this way, we generalize Levy’s covariant treatment ofS wave scattering. The result of the calculation is deeply modified by the introduction of these new processes. It is not possible to get a quantitative agreement with experiment. The signs of the phase shifts, however, are correct near G2/4π = 15. The approximations used in solving the integral equations are discussed by comparison with other calculations.