The LoopTools interface allows to quickly evaluate Passarino-Veltman functions with suitable kinematics numerically using LoopTools.
Given an amplitude written in terms of
PaVe-functions
amp = Get[FileNameJoin[{$FeynHelpersDirectory, "Documentation", "Examples", "ampHToGG.m"}]];we can evaluate it by first loading LoopTools via
LToolsLoadLibrary[]and then running
ampEval = LToolsEvaluate[amp, LToolsSetMudim -> 1, InitialSubstitutions -> {mH -> 125, mt -> 173}]where we set \mu = 1. The resulting expression is then
Collect2[ampEval /. {D -> 4, mH -> 125, mt -> 173}, Pair]