New representation of the two-loop crossed vertex function

Abstract

We calculate the two-loop vertex function for the crossed topology, and for arbitrary masses and external momenta. We derive a double integral representation, suitable for a numerical evaluation by a Gaussian quadrature. Real and imaginary parts of the diagram can be calculated separately.

Comments: 16 pages, latex, uses epsfig, amstex, amssymb. Replacement has typo corrected, references updated