Pion electroproduction in a nonrelativistic theory

TL;DR

This paper develops a nonrelativistic effective theory for pion electroproduction on nucleons, providing detailed multipole amplitudes and a new low energy theorem, enhancing understanding of low-energy pion-nucleon interactions.

Contribution

It introduces a nonrelativistic framework specifically tailored to describe pion electroproduction and includes two-loop calculations for all reaction channels.

Findings

Calculated S- and P-wave multipole amplitudes at two loops.

Provided a new low energy theorem.

Accurately describes the cusp due to pion and nucleon mass differences.

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.