Resummation of threshold corrections in QCD to power accuracy: the Drell-Yan cross section as a case study

TL;DR

The paper tackles threshold resummation in QCD and the risk of introducing spurious power corrections. It contrasts LLA-based and Wilson-line resummation frameworks to enforce infrared consistency with finite-order diagrams. The analysis shows that when soft gluon emissions, including large-angle contributions, are treated coherently, artificial 1/Q infrared terms cancel and genuine power corrections to Drell-Yan are suppressed at least to order 1/Q^2, with initial-condition effects governing remaining power behavior. The work also highlights theoretical uncertainties in top-quark production resummation and discusses the implications for event-shape observables, emphasizing the need for angle-inclusive, renormalization-group–level resummation approaches.

Abstract

Resummation of large infrared logarithms in perturbation theory can, in certain circumstances, enhance the sensitivity to small gluon momenta and introduce spurious nonperturbative contributions. In particular, different procedures -- equivalent in perturbation theory -- to organize this resummation can differ by $1/Q$ power corrections. The question arises whether one can formulate resummation procedures that are explicitly consistent with the infrared behaviour of finite-order Feynman diagrams. We explain how this problem can be treated and resolved in Drell-Yan (lepton pair) production and briefly discuss more complicated cases, such as top quark production and event shape variables in the $e^+e^-$ annihilation.