The $n_f$ terms of the three-loop cusp anomalous dimension in QCD

Abstract

In this talk we present the result for the $n_f$ dependent piece of the three-loop cusp anomalous dimension in QCD. Remarkably, it is parametrized by the same simple functions appearing in analogous anomalous dimensions in $\mathcal{N}=4$ SYM at one and two loops. We also compute all required master integrals using a recently proposed refinement of the differential equation method. The analytic results are expressed in terms of harmonic polylogarithms of uniform weight.

Comments: 8 pages, 2 figures; v2: typo in eq. (4.4) fixed, 'three-loop' added to title