A simple introduction to soft resummation
Abstract
We provide an elementary pedagogical introduction to some basic concepts and techniques of soft (or Sudakov) resummation, specifically in QCD, paying particular attention to simple but useful tricks of the trade. We briefly review collinear (Altarelli-Parisi) and infrared (eikonal)factorization, cancellation of infrared singularities and factorization of mass singularities. We recall basic concepts on renormalization group invariance and the solution of renormalization group equations. We then show how threshold resummation can be derived from a renormalization group argument following from the cancellation of infrared singularities. We discuss various equivalent forms of the resummed result, and we briefly present transverse momentum resummation.
Keywords
Cite
@article{arxiv.2511.17704,
title = {A simple introduction to soft resummation},
author = {Stefano Forte and Giovanni Ridolfi},
journal= {arXiv preprint arXiv:2511.17704},
year = {2026}
}
Comments
34 pages, 7 figures. Final version, as published on Acta Physica Polonica (a few remaining minor typos corrected)