High Energy Theory Seminar

The cusp anomalous dimension is an ubiquitous quantity in four-dimensional gauge theories. It governs the dependence of a cusped Wilson loop on the ultraviolet cut-off and appears in many physical quantities. In particular, it controls the infrared asymptotics of scattering amplitudes
and form factors involving massive particles. The two-loop result for this fundamental quantity has been known for more than 25 years. Here we report on the full result for the cusp anomalous dimension in QCD at three loops.