Towards Automatic Analytic Evaluation of Diagrams with Masses

Abstract

A method to calculate two-loop self-energy diagrams of the Standard Model is demonstrated. A direct physical application is the calculation of the two-loop electroweak contribution to the anomalous magnetic moment of the muon ${1/2(g-2)}_{\mu }$. Presently, we confine ourselves to a ``toy'' model with only $\mu$, $\gamma$ and a heavy neutral scalar particle (Higgs). The algorithm is implemented as a FORM-based program package. For generating and automatically evaluating any number of two-loop self-energy diagrams, a special C-program has been written. This program creates the initial FORM-expression for every diagram generated by QGRAF, executes the corresponding subroutines and sums up the final results.

Comments: LaTeX, 20 pages, 7 eps-figures included; extended version of talk given at AIHEN96, Lausanne, 1-6 Sept. 1996; detailed description of C-program is given; accepted for publication in Comp.Phys.Comm