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Reduction and evaluation of two-loop graphs with arbitrary masses

A. Ghinculov·Y. -P. Yao
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Abstract

We describe a general analytic-numerical reduction scheme for evaluating any 2-loop diagrams with general kinematics and general renormalizable interactions, whereby ten special functions form a complete set after tensor reduction. We discuss the symmetrical analytic structure of these special functions in their integral representation, which allows for optimized numerical integration. The process Z -> bb is used for illustration, for which we evaluate all the 3-point, non-factorizable g^2*alpha_s mixed electroweak-QCD graphs, which depend on the top quark mass. The isolation of infrared singularities is detailed, and numerical results are given for all two-loop three-point graphs involved in this process.

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A. Ghinculov, Y. -P. Yao. 2000-06-28. Reduction and evaluation of two-loop graphs with arbitrary masses. https://doi.org/10.1103/physrevd.63.054510

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