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Factorizing one-loop contributions to two-loop Bhabha scattering and automatization of Feynman diagram calculations

J. Fleischer·O. V. Tarasov·T. Riemann·A. Werthenbach
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Abstract

In higher order calculations a number of new technical problems arise: one needs diagrams in arbitrary dimension in order to obtain their needed $ε$-expansion, zero Gram determinants appear, renormalization produces diagrams with `dots' on the lines, i.e. higher order powers of scalar propagators. All these problems cannot be accessed by the `standard' Passarino-Veltman approach: there is not available what is needed for higher loops. We demonstrate our method of how to solve these problems.

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J. Fleischer, O. V. Tarasov, T. Riemann, A. Werthenbach. 2002-10-11. Factorizing one-loop contributions to two-loop Bhabha scattering and automatization of Feynman diagram calculations. https://doi.org/10.1016/s0168-9002(03)00504-7

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