Next-to-leading power threshold effects for inclusive and exclusive processes with final state jets

TL;DR

This paper investigates next-to-leading power threshold effects in QCD processes with jets, deriving a universal amplitude for soft gluons and quarks, and demonstrating its application across various scattering processes to improve resummation accuracy.

Contribution

It introduces a universal NLP amplitude for soft emissions applicable to multiple processes, advancing the understanding of subleading power corrections in QCD.

Findings

Derived an NLP amplitude for soft gluons and quarks.

Validated the framework in DIS, e+e- annihilation, and prompt photon production.

Contributes to developing a universal NLP resummation formalism.

Abstract

It is well known that cross-sections in perturbative QCD receive large corrections from soft and collinear radiation, whose properties must be resummed to all orders in the coupling. Whether or not the universal properties of this radiation can be extended to next-to-leading power (NLP) in the threshold expansion has been the subject of much recent study. In this paper, we consider two types of NLP effects: the interplay of next-to-soft and collinear radiation in processes with final state jets and the NLP contributions stemming from soft quarks. We derive an NLP amplitude for soft gluons and quarks, valid for an arbitrary number of coloured or colourless massless final state particles. We show explicitly that this framework can be used to correctly obtain the dominant NLP effects in three different types of processes at next-to-leading order: deep-inelastic scattering, hadroproduction via electron-positron annihilation and prompt photon production. Our results provide an important ingredient for developing a universal resummation formalism for NLP effects.