Comments on regularization ambiguities and local gauge symmetries

We study the regularization ambiguities in an exact renormalized (1+1)-dimensional field theory. We show a relation between the regularization ambiguities and the coupling parameters of the theory as well as their role in the implementation of a local gauge symmetry at quantum level.Comment: Latex 2e, 4 pages. To appear in Modern Physics Letters

General CPT-even dimension-five nonminimal couplings between fermions and photons yielding EDM and MDM

In this letter, we examine a new class of CPT-even nonminimal interactions, between fermions and photons, deprived of higher order derivatives, that yields electric dipole moment (EDM) and magnetic dipole moment (MDM) in the context of the Dirac equation. The couplings are dimension-five CPT-even and Lorentz-violating nonminimal structures, composed of a rank-2 tensor, $T_{\mu\nu}$, the electromagnetic tensor, and gamma matrices, being addressed in its axial and non-axial Hermitian versions, and also comprising general possibilities. We then use the electron's anomalous magnetic dipole moment and electron electric dipole moment measurements to reach upper bounds of $1$ part in $10^{20}$ and $10^{25}$ (eV )$^{-1}$