AuxiliaryMomenta is an option of
FCLoopPropagatorsToLineMomenta,
FCLoopIntegralToGraph and other functions. It specifies
auxiliary momenta that do not correspond to external legs, i.e. don’t
really flow through the lines, e.g.
and in SCET or in HQET.
Overview, FCLoopPropagatorsToLineMomenta, FCLoopIntegralToGraph.