Nonlinear gauge-fixing in the FeynArts package
Jurgis Pašukonis · Lithuanian Journal of Physics · 2007
Accurate calculations in the Standard Model (SM) that match the experimental accuracy require the generation and evaluation of Feynman diagrams up to one-or even two-loop order, where there can be hundreds of diagrams.Programs like FeynArts or GRACE can do this in an automated way.In order to check the reliability, one can test if the result is independent of the gauge-fixing parameters.Nonlinear gauge-fixing, as proposed by F. Boudjema and E. Chopin, introduces more parameters, so the test is more stringent.In this paper we present the implementation of nonlinear gauge-fixing into the model files for FeynArts and discuss the gauge invariance of diagrams that are generated by FeynArts with the use of our model files.