Next-to-leading power threshold logarithms: a status report

TL;DR

This paper reviews recent progress in understanding and resumming next-to-leading power threshold logarithms in electroweak processes, extending the universality of soft emissions beyond leading power.

Contribution

It summarizes recent developments that advance the formalism for threshold resummation beyond leading power, especially for electroweak annihilation processes.

Findings

Progress in formalism for next-to-leading power resummation

Partial success of phenomenological approaches

Potential for systematic resummation beyond leading power

Abstract

There is ample evidence, dating as far back as Low's theorem, that the universality of soft emissions extends beyond leading power in the soft energy. This universality can, in principle, be exploited to generalise the formalism of threshold resummations beyond leading power in the threshold variable. In the past years, several phenomenological approaches have been partially successful in performing such a resummation. Here, we briefly review some recent developments which pave the way to a solution of this problem, at least for electroweak annihilation processes.