Pion photoproduction in a nonrelativistic theory
arXiv:0909.3121 · doi:10.1016/j.physletb.2009.12.008
Abstract
The pion and nucleon mass differences generate a very pronounced cusp in the photoproduction reaction of a single pion on the nucleon. A nonrelativistic effective field theory to describe this reaction is constructed. The approach is rigorous in the sense that it is an effective field theory with a consistent power counting scheme. Expressions for the S- and P-wave multipole amplitudes for all four reaction channels at two loops are given.
13 pages, 2 figures