# Effective Field Theories in R_xi gauges

## TL;DR

This paper develops a comprehensive framework for incorporating higher-dimensional operators into R_xi gauges in effective quantum field theories, ensuring consistent gauge fixing and Feynman rules for operators of any dimension.

## Contribution

It introduces a generalized gauge fixing procedure and ghost sector for effective theories with arbitrary dimension operators, extending previous Standard Model EFT results.

## Key findings

- Consistent gauge fixing for higher-dimensional operators
- Extension of R_xi gauges to arbitrary operator dimensions
- Framework applicable to a broad class of effective theories

## Abstract

In effective quantum field theories, higher dimensional operators can affect the canonical normalization of kinetic terms at tree level. These contributions for scalars and gauge bosons should be carefully included in the gauge fixing procedure, in order to end up with a convenient set of Feynman rules. We develop such a setup for the linear R_xi-gauges. It involves a suitable reduction of the operator basis, a generalized gauge fixing term, and a corresponding ghost sector. Our approach extends previous results for the dimension-six Standard Model Effective Field Theory to a generic class of effective theories with operators of arbitrary dimension.