Radiative generation of the CPT-even gauge term of the SME from a dimension-five nonminimal coupling term

TL;DR

This paper demonstrates that the CPT-even gauge term of the SME can be generated through quantum corrections in a modified QED with a dimension-five nonminimal coupling, allowing for tighter bounds on the coupling parameters.

Contribution

It introduces a novel mechanism for generating the CPT-even gauge term of the SME via radiative corrections in a gauge-invariant manner within a modified QED framework.

Findings

Bounds on nonminimal coupling are improved by factors of 10^5 to 10^25.

The nonminimal coupling induces higher-order derivative terms in the gauge field effective action.

The CPT-even gauge term can be radiatively generated from a dimension-five nonminimal interaction.

Abstract

In this letter we show for the first time that the usual CPT-even gauge term of the standard model extension (SME) can be radiatively generated, in a gauge invariant level, in the context of a modified QED endowed with a dimension-five nonminimal coupling term recently proposed in the literature. As a consequence, the existing upper bounds on the coefficients of the tensor $(K_{F}) $ can be used improve the bounds on the magnitude of the nonminimal coupling, $\lambda(K_{F}),$ by the factors $10^{5}$ or $10^{25}.$ The nonminimal coupling also generates higher-order derivative contributions to the gauge field effective action quadratic terms.