Exact calculation of the radiatively-induced Lorentz and CPT violation in QED

TL;DR

This paper computes the exact one-loop radiative correction to the Lorentz- and CPT-violating Chern-Simons term in QED, demonstrating it matches the lowest-order result in relevant cases, with implications for regularization and renormalization.

Contribution

It provides the exact calculation of the radiatively-induced Lorentz and CPT violation in QED, including full dependence on the axial coupling parameter b_mu.

Findings

Exact one-loop correction matches lowest-order result in key cases

Regularization and renormalization effects are discussed

Implications for Lorentz and CPT violation in QED are clarified

Abstract

Radiative corrections arising from the axial coupling of charged fermions to a constant vector b_\mu can induce a Lorentz- and CPT-violating Chern-Simons term in the QED action. We calculate the exact one-loop correction to this term keeping the full b_\mu dependence, and show that in the physically interesting cases it coincides with the lowest-order result. The effect of regularization and renormalization and the implications of the result are briefly discussed.