Pion electroproduction in a nonrelativistic theory

Abstract

A nonrelativistic effective theory to describe the electroproduction reaction of a single pion on the nucleon at leading order in the electromagnetic coupling is constructed. The framework is tailored to accurately describe the cusp generated by the pion and nucleon mass differences. The S- and P- wave multipole amplitudes at two loops for all four reaction channels are provided. As an application, a new low energy theorem is discussed.