The Self-energy of Nucleon for the Photoproduction of Pion in the Low-energy Region

Abstract

The scattering amplitude of the photoproduction of $\pi^{+}$ is calculated using the helicity formalism. The pseudovector coupling $\pi$-N interaction with the non-perturbative term is applied to the perturbative expansion. The parameters for the self-energy are taken from the results of the $\pi$-N scattering in our previous study.