Unification of Photoproduction and Electroproduction

Abstract

Gauge invariance and the vector nature of the photon are exploited in order to factor expressions for cross sections of photon-induced reactions into a purely kinematical part and a purely dynamical part. Detailed studies of two-and three-body final states are considered and it is shown how this separation into kinematical and dynamical aspects provides a useful and general procedure by which to compare experiment and theory.