Equivalence of pion loops in equal-time and light-front dynamics

Abstract

We demonstrate the equivalence of the light-front and equal-time formulations of pionic corrections to nucleon properties. As a specific example, we consider the self-energy Σ of a nucleon dressed by pion loops, for both pseudovector and pseudoscalar πNN couplings. We derive the leading and next-to-leading nonanalytic behavior of Σ on the light front, and show explicitly their equivalence in the rest frame and infinite momentum frame in equal-time quantization, as well as in a manifestly covariant formulation.