On the Gauge-Invariant Fermion

TL;DR

This paper demonstrates that the Dirac dressing of fermions effectively shifts the gauge parameter, ensuring gauge invariance of physical observables and showing that non-locality and path dependence are not physical obstacles.

Contribution

It establishes the equivalence between Dirac dressing and gauge parameter shifts, clarifying gauge invariance and physical mass consistency across different dressings.

Findings

Gauge-dependent parts are projected out of observables.

Physical mass remains unchanged after renormalization.

Non-locality and path dependence are non-physical artifacts.

Abstract

We show that the Dirac dressing of the fermion is equivalent to a shift of the gauge parameter. For every gauge, the gauge-dependent part is projected out of physical observables. After renormalization, the physical mass is the same for every dressing. The non-locality, compositeness and path dependence associated with the dressing are therefore not physical obstructions.