On the four-loop strong coupling beta-function in the SM

Abstract

In the talk the leading four-loop contribution to the beta-function of the strong coupling in the SM is discussed. Some details of calculation techniques are provided. Special attention is paid to the ambiguity due to utilized ${\gamma }_5$ treatment and a particular prescription with anticommuting ${\gamma }_5$ is advocated. As a by-product of our computation the four-loop beta-function in QCD with "gluino" is also obtained.

Comments: 6 pages, 2 figures, submitted to Proceedings of 19th International Seminar on High Energy Physics "QUARKS-2016", Pushkin, Russia, May-June, 2016