Infrared renormalization of two-loop integrals and the chiral expansion of the nucleon mass

TL;DR

This paper details the infrared renormalization process for two-loop integrals in chiral perturbation theory, enabling precise calculation of the nucleon mass expansion while maintaining symmetries.

Contribution

It introduces a method for infrared renormalization of two-loop integrals that preserves symmetries and adheres to power counting in chiral perturbation theory.

Findings

Renormalization preserves chiral symmetry.

Calculated nucleon mass expansion up to order O(q^6).

Diagrams respect standard power counting rules.

Abstract

We describe details of the renormalization of two-loop integrals relevant to the calculation of the nucleon mass in the framework of manifestly Lorentz-invariant chiral perturbation theory using infrared renormalization. It is shown that the renormalization can be performed while preserving all relevant symmetries, in particular chiral symmetry, and that renormalized diagrams respect the standard power counting rules. As an application we calculate the chiral expansion of the nucleon mass to order O(q^6).