Abstract / Description of output
We perform a case study of the behaviour of gluon radiation beyond the soft approximation, using as an example the Drell-Yan production cross section at NNLO. We draw a careful distinction between the eikonal expansion, which is in powers of the soft gluon energies, and the expansion in powers of the threshold variable 1 - z, which involves important hard-collinear effects. Focusing on the contribution to the NNLO Drell-Yan K-factor arising from real-virtual interference, we use the method of regions to classify all relevant contributions up to next-to-leading power in the threshold expansion. With this method, we reproduce the exact two-loop result to the required accuracy, including z-independent non-logarithmic contributions, and we precisely identify the origin of the soft-collinear interference which breaks simple soft-gluon factorisationat next-to-eikonal level. Our results pave the way for the development of a general factorisation formula for next-to-leading-power threshold logarithms, and clarify the nature of loop corrections to a set of recently proposed next-to-soft theorems. (C) 2015 The Authors. Published by Elsevier B.V.
Original language | English |
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Pages (from-to) | 375-382 |
Number of pages | 8 |
Journal | Physics Letters B |
Volume | 742 |
DOIs | |
Publication status | Published - 6 Mar 2015 |
Keywords / Materials (for Non-textual outputs)
- LEPTON-PAIR PRODUCTION
- HIGGS-BOSON
- LARGE-X
- ASYMPTOTIC-EXPANSION
- FEYNMAN-INTEGRALS
- CROSS-SECTIONS
- GLUON-FUSION
- K-FACTOR
- RESUMMATION
- QCD