Implementation of non-linear gauge-fixing in FeynArts package

TL;DR

This paper derives and implements non-linear gauge-fixing Feynman rules for the Standard Model in the FeynArts package, ensuring gauge invariance and proper renormalization at tree and one-loop levels.

Contribution

It introduces non-linear gauge-fixing rules into FeynArts and demonstrates their compatibility with gauge invariance and renormalization in Standard Model calculations.

Findings

Tree-level amplitudes are gauge invariant.

Renormalization remains consistent at one-loop level.

FeynArts model files are publicly available.

Abstract

Feynman rules for the Standard Model including non-linear gauges are derived and implemented in the FeynArts package. The calculations using FeynArts with the new rules show that tree-level amplitudes are gauge invariant and that renormalization is not spoiled for one-loop calculations. The FeynArts model files are available at http://www.fi.lt/~garfield/SM/