All-order results for soft and collinear gluons

TL;DR

This paper reviews the resummation of infrared and collinear divergences in QCD and non-abelian gauge theories, highlighting recent advances and the role of exponentiation, with a focus on conformal theories like N=4 super Yang-Mills.

Contribution

It provides a concise overview of the field-theoretical methods for resummation and discusses recent results in the conformal limit, especially for N=4 SYM.

Findings

Exponentiation of divergences underpins resummation techniques.

Recent results in N=4 super Yang-Mills theory highlight conformal invariance.

Field-theoretical tools are essential for understanding long-distance singularities.

Abstract

I briefly review some general features and some recent developments concerning the resummation of long-distance singularities in QCD and in more general non-abelian gauge theories. I emphasize the field-theoretical tools of the trade, and focus mostly on the exponentiation of infrared and collinear divergences in amplitudes, which underlies the resummation of large logarithms in the corresponding cross sections. I then describe some recent results concerning the conformal limit, notably the case of N = 4 superymmetric Yang-Mills theory