Abstract
We study next-to-leading-power (NLP) threshold corrections in colour-singlet production processes, with particular emphasis on Drell-Yan (DY) and single-Higgs production. We assess the quality of the partonic and hadronic threshold expansions for each process up to NNLO. We determine numerically the NLP leading-logarithmic (LL) resummed contribution in addition to the leading-power next-to-next-to-leading logarithmic (LP NNLL) resummed DY and Higgs cross sections, matched to NNLO. We find that the inclusion of NLP logarithms is numerically more relevant than increasing the precision to N3LL at LP for these processes. We also perform an analytical and numerical comparison of LP NNLL + NLP LL resummation in soft-collinear effective theory and direct QCD, where we achieve excellent analytical and numerical agreement once the NLP LL terms are included in both formalisms. Our results underline the phenomenological importance of understanding the NLP structure of QCD cross sections.
Highlights
Logarithms of the threshold variable ξ in these corrections
The threshold expansion of the off-diagonal qg-channel in Higgs production converges only very slowly, whereas for DY convergence is already obtained after including the N4LP contribution
We reviewed the resummation of leading-logarithmic NLP corrections in direct QCD (dQCD) in section 3, and derived a slightly improved resummed expression involving a derivative with respect to the Mellin moment (eq (3.25))
Summary
We study the convergence of the threshold expansion in fixed order calculations for the single Higgs and the DY processes, first at the parton level, and subsequently for the hadronic cross section. [9, 40,41,42,43,44,45, 53,54,55,56]) have addressed partonic and/or hadronic threshold expansions for one or both of these processes, we provide here an extended analysis tailored to study NLP corrections.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
