Leading Chiral Logarithms for Pion Form Factors to Arbitrary Number of Loops

TL;DR

This paper introduces a method to calculate leading chiral logarithms at any loop order for Nambu-Goldstone boson form factors, demonstrated on sigma-models, and sums these logs in the large N limit.

Contribution

It presents a novel method for calculating and summing leading chiral logarithms for form factors at arbitrary loop levels in sigma-models.

Findings

Method for arbitrary loop order calculations developed.

Analytical properties of form factors derived.

Leading logarithms summed in large N limit.

Abstract

We develop the method of calculation of the leading chiral (infrared) logarithms to an arbitrary loop order for various form factors of Nambu-Goldstone bosons. The method is illustrated on example of scalar and vector form factors in massless 4D O(N+1)/O(N) sigma-model. The analytical properties of the form factors are derived. The leading chiral (infrared) logarithms are summed up in the large N limit.