The Gluon Beam Function at Two Loops
Abstract
The virtuality-dependent beam function is a universal ingredient in the resummation for observables probing the virtuality of incoming partons, including N-jettiness and beam thrust. We compute the gluon beam function at two-loop order. Together with our previous results for the two-loop quark beam function, this completes the full set of virtuality-dependent beam functions at next-to-next-to-leading order (NNLO). Our results are required to account for all collinear ISR effects to the N-jettiness event shape through N^3LL order. We present numerical results for both the quark and gluon beam functions up to NNLO and N^3LL order. Numerically, the NNLO matching corrections are important. They reduce the residual matching scale dependence in the resummed beam function by about a factor of two.
Cite
@article{arxiv.1405.1044,
title = {The Gluon Beam Function at Two Loops},
author = {Jonathan Gaunt and Maximilian Stahlhofen and Frank J. Tackmann},
journal= {arXiv preprint arXiv:1405.1044},
year = {2015}
}
Comments
21 pages, 6 figures; v2: journal version