Analysis of the consistency of parity-odd nonbirefringent modified Maxwell theory

作者：Schreck M^*

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 86(6): 065038.

DOI：10.1103/PhysRevD.86.065038

There exist two deformations of standard electrodynamics which describe Lorentz symmetry violation in the photon sector: CPT-odd Maxwell-Chern-Simons theory and CPT-even modified Maxwell theory. In this article, we focus on the parity-odd nonbirefringent sector of modified Maxwell theory. It is coupled to a standard Dirac theory of massive spin-1/2 fermions resulting in a modified quantum electrodynamics (QED). This theory is discussed with respect to properties such as microcausality and unitarity, where it turns out that these hold. Furthermore, a priori, the limit of the theory for vanishing Lorentz-violating parameters seems to be discontinuous. The modified photon polarization vectors are interweaved with preferred spacetime directions defined by the theory, and one vector even has a longitudinal part. That structure remains in the limit mentioned. Since it is not clear whether or not this behavior is a gauge artifact, the cross section for a physical process-modified Compton scattering-is calculated numerically. Despite the numerical instabilities occurring for scattering of unpolarized electrons off polarized photons in the second physical polarization state, it is shown that for Lorentz-violating parameters much smaller than one, the modified cross sections approach the standard QED results. Analytical investigations strengthen the numerical computations. Hence, the theory proves to be consistent, at least with regard to the investigations performed. This leads to the interesting outcome of the modification being a well-defined parity-odd extension of QED.

• 出版日期2012-9-26