General Procedure of Gauge Fixings and Ghosts

TL;DR

This paper revisits the BRST-based gauge fixing procedure, demonstrating its validity at all orders and correctly deriving the structure of ghosts, including the 'third ghost', especially in higher-derivative gauge fixings.

Contribution

It provides a symmetry-based, all-order consistent method for gauge fixings and ghosts, extending previous one-loop results to full order.

Findings

Correct structure of gauge fixings and ghosts including 'third ghost'

Applicability to higher-derivative gauge fixings

Validity at full order based on symmetry principle

Abstract

We revisit the general procedure of gauge fixings and ghosts based on BRST invariance principle. It is shown that when this is applied to the higher-derivative gauge fixings, it gives the correct structure of gauge fixings and ghosts including "third ghost", previously derived at one-loop level. This procedure is solely based on the symmetry principle and is valid at full order.