Massive Two-Loop Integrals and Higgs Physics

TL;DR

This paper introduces XLOOPS 1.0, an automated tool for calculating complex two-loop Feynman diagrams in the Standard Model, with applications to Higgs decay analysis.

Contribution

It presents a new computational program capable of handling massive two-loop integrals and their tensor structures, advancing precision in Higgs physics calculations.

Findings

Successful calculation of Higgs decay at two-loop level

Reduction of two-loop integrals to two-fold numerical integrals

Explicit handling of UV divergences in dimensional regularization

Abstract

We describe in some detail the present features of an automatic loop calculation program as well as the integration techniques that go into it. The program, called XLOOPS 1.0, allows one to calculate massive one- and two-loop Feynman diagrams in the Standard Model including their tensor structure. UV divergences in UV divergent integrals are explicitly computed in dimensional regularization. One-loop integrals are calculated analytically in d \neq 4 dimensions whereas two-loop integrals are reduced to two-fold integral representations which the program evaluates numerically. We discuss Higgs decay at the two-loop level as a first application of the novel integration techniques that are incorporated into XLOOPS.