Four-dimensional differential equations for the leading divergences of dimensionally-regulated loop integrals

Abstract

We invent an automated method for computing the divergent part of Feynman integrals in dimensional regularization. Our method exploits simplifications from four-dimensional integration-by-parts identities. Leveraging algorithms from the literature, we show how to find simple differential equations for the divergent part of Feynman integrals. We illustrate the method by an application to heavy quark effective theory at three loops.

Comments: third version with minor changes and two additional supplemental directories