Reduction of Feynman Integrals in the Parametric Representation III: Integrals with Cuts
arXiv:2007.00507 · doi:10.1140/epjc/s10052-020-08757-3
Abstract
Phase space cuts are implemented by inserting Heaviside theta functions in the integrands of momentum-space Feynman integrals. By directly parametrizing theta functions and constructing integration-by-parts (IBP) identities in the parametric representation, we provide a systematic method to reduce integrals with cuts. Since the IBP method is available, it becomes possible to evaluate integrals with cuts by constructing and solving differential equations.
6 pages, 1 figure, matches published version