The off-Shell Electromagnetic Vertex of the Nucleon in Chiral Perturbation Theory

Abstract

We study the electromagnetic vertex of a nucleon in next-to-leading order chiral perturbation theory (CPT). We consider the case where one of the nucleons at the $\gamma$NN vertex is off its mass shell. We define relevant measures for the off-shell dependence in the limited kinematical range allowed, and analyze their expansion in the pion mass. The leading nonanalytic contributions are calculated to estimate their size.

Comments: 12 pages (LaTeX), 1 figure (available upon request), NIKHEF 93-P1