One-particle exchange theory of pion photoproduction: I. General calculation

Abstract

A calculation of single pion photoproduction from single nucleons is given using the one-particle exchange model involving the exchange of one pion, one ϱ, one ω, one φ, one nucleon, one N ∗ , and one N ∗∗ . Crossed diagrams, previously neglected, have also been included in the calculation. An imaginary part of the amplitudes is included using a Breit-Wigner type formula and experimentally observed widths. The theory should be a good representation of pion photoproduction up to about 800 MeV incident laboratory photon energy. A numerical evaluation of the theory will be given in a subsequent paper.