EVALUATION OF MULTIPOLES FOR PHOTO- AND ELECTROPRODUCTION OF PIONS .2. NUMERICAL RESULTS FOR PHOTOPRODUCTION OF PIONS ON PROTONS

In this paper we present the detailed results of an evaluation of the multipole amplitudes for photoproduction of pions on nucleons. We have solved the dispersion relations for the multipoles E0+, M1-, M1+, E1+, E2-2 and M2- by the Muskhelishvili-Omnès method using an appropriate ansatz for the inelastic multipole amplitudes. Four phenomenological parameters occuring in our theory have been determined by a least squares fit of the π0 experimental different cross section data. Except at pion CM-angles between 50°0 and 80°0 and at 180°0 in π0 production there is satisfactory agreement between theory and experiment for all measured differential cross sections, polarizations and asymmetries of π0- and π+-photoproduction. © 1969 Springer-Verlag.