The method of regions and next-to-soft corrections in Drell–Yan production
Oct 23, 2014
8 pages
Published in:
- Phys.Lett.B 742 (2015) 375-382
- Published: Mar 6, 2015
e-Print:
- 1410.6406 [hep-ph]
Report number:
- EDINBURGH-2014-18,
- NIKHEF-2014-039,
- ITF-UU-14-24
View in:
Citations per year
Abstract: (Elsevier)
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 factorisation at 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.Note:
- 18 pages, 1 figure
- Drell-Yan process
- gluon: fusion
- gluon: radiation
- gluon: energy
- gluon: collinear
- approximation: eikonal
- approximation: higher-order
- threshold: correction
- threshold: expansion
- expansion: higher-order
References(60)
Figures(1)
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
- [13]
- [14]
- [15]
- [16]
- [17]
- [18]
- [19]
- [20]
- [21]
- [22]
- [23]
- [24]
- [25]