Constraining CPT-even and Lorentz-violating nonminimal couplings with the electron magnetic and electric dipole moments

TL;DR

This paper investigates CPT-even, Lorentz-violating nonminimal couplings in the Dirac equation, deriving bounds from electron magnetic and electric dipole moments that significantly tighten existing constraints.

Contribution

It introduces new bounds on dimension-five CPT-even, Lorentz-violating couplings using precision electron dipole moment measurements, improving restrictions by at least 8 orders of magnitude.

Findings

Upper bounds of 1 part in 10^{20} and 10^{24} (eV)^{-1} on couplings

Constraints transferred to Sun-centered frame considering Earth's rotation

Significant tightening of previous limits on Lorentz-violating couplings

Abstract

We analyse some dimension-five CPT-even and Lorentz-violating nonminimal couplings between fermionic and gauge fields in the context of the Dirac equation. After evaluating the nonrelativistic Hamiltonian, we discuss the behavior of the terms under discrete symmetries and analyse the implied effects. We then use the anomalous magnetic dipole moment and electron electric dipole moment measurements to reach upper bounds of $1$ part in $10^{20}$ and $10^{24}$ $\left( eV\right) ^{-1}$, improving the level of restriction on such couplings by at least 8 orders of magnitude. These upper bounds are also transferred to the Sun-centered frame by considering the Earth's rotational motion.