# SmeftFR -- Feynman rules generator for the Standard Model Effective Field Theory

## TL;DR

SmeftFR is a Mathematica package that automates the generation of Feynman rules for the Standard Model Effective Field Theory, including all gauge-invariant operators up to dimension 6, facilitating theoretical and phenomenological analyses.

## Contribution

It provides a comprehensive, user-friendly tool for deriving Feynman rules in SMEFT with flexible options for gauge fixing, neutrino treatment, and output formats, enhancing research efficiency.

## Key findings

- Generates complete Feynman rules for SMEFT up to dimension 6.
- Supports various gauges and neutrino treatments.
- Exports in multiple formats and includes a LaTeX generator.

## Abstract

We present SmeftFR, a Mathematica package designed to generate the Feynman rules for the Standard Model Effective Field Theory (SMEFT) including the complete set of gauge invariant operators up to dimension~6. Feynman rules are generated with the use of FeynRules package, directly in the physical (mass eigenstates) basis for all fields. The complete set of interaction vertices can be derived including all or any chosen subset of SMEFT operators. As an option, the user can also choose preferred gauge fixing, generating Feynman rules in unitary or $R_\xi$-gauges (the latter include generation of ghost vertices). Further options allow to treat neutrino fields as massless Weyl or massive Majorana fermions. The derived Lagrangian in the mass basis can be exported in various formats supported by FeynRules, such as UFO, FeynArts, etc. Initialisation of numerical values of $d=6$ Wilson coefficients used by SmeftFR is interfaced to WCxf format. The package also includes dedicated Latex generator allowing to print the result in clear human-readable form. SmeftFR can be downloaded from www.fuw.edu.pl/smeft.