QED with chiral nonminimal coupling: aspects of the Lorentz-violating quantum corrections

TL;DR

This paper investigates a Lorentz-violating extension of QED with a chiral nonminimal coupling, showing it induces a CPT-even Lorentz-breaking photon term and discussing its nonrenormalizability.

Contribution

It demonstrates that a chiral nonminimal coupling in QED naturally generates a CPT-even Lorentz-violating photon term, highlighting the model's nonrenormalizability and comparing it to non-chiral cases.

Findings

Lorentz-violating term is generated by the chiral coupling

The chiral coupling requires the Lorentz-breaking term to be present initially

The model is nonrenormalizable

Abstract

An effective model for QED with the addition of a nonminimal coupling with a chiral character is investigated. This term, which is proportional to a fixed 4-vector $b_\mu$, violates Lorentz symmetry and may originate a CPT-even Lorentz breaking term in the photon sector. It is shown that this Lorentz breaking CPT-even term is generated and that,in addition, the chiral nonminimal coupling requires this term is present from the beginning. The nonrenormalizability of the model is invoked in the discussion of this fact and the result is confronted with the one from a model with a Lorentz-violating nonminimal coupling without chirality.