Large momentum expansion of two-loop self-energy diagrams with arbitrary masses

Abstract

For two-loop two-point diagrams with arbitrary masses, an algorithm to derive the asymptotic expansion at large external momentum squared is constructed. By using a general theorem on asymptotic expansions of Feynman diagrams, the coefficients of the expansion are calculated analytically. For some two-loop diagrams occurring in the Standard Model, comparison with results of numerical integration shows that our expansion works well in the region above the highest physical threshold.Comment: Preprint INLO-PUB--5/93 (Instituut-Lorentz, University of Leiden, February 1993), 19 pages, 5 figures (two fugures included in the LaTEX file, and three figures added at the end as poscript-files; see information in the beginning of the file; copies of fugures can also be requested by e-mail: [email protected]