Lorentz and CPT violations from Chern-Simons modifications of QED

Abstract

The possibility of a small modification of spinor Quantum Electro-Dynamics is reconsidered, in which Lorentz and CPT non-covariant kinetic terms for photons and fermions are present. The corresponding free field theory is carefully discussed. The finite one-loop parity-odd induced effective action is unambiguously calculated using the physical cutoff method, which manifestly encodes the maximal residual symmetry group allowed by the presence of the Lorentz and CPT breaking axial-vector. This very same induced effective action, which is different from those ones so far quoted in the Literature, is also re-derived by means of the dimensional regularization, provided the maximal residual symmetry is maintained in the enlarged D-dimensional space-time. As a consequence, it turns out that the requirement of keeping the maximal residual symmetry at the quantum level just corresponds to the physical renormalization prescription which naturally fixes the one-loop parity-odd induced effective action.

Consequences of a condensed matter realization of Lorentz-violating QED in Weyl semi-metals

“…In high energy physics, particularly in the context of potential extensions to the standard model, the possibility of a violation of Lorentz symmetries in QED of the form (1) has been subject of intense theoretical research over more than a decade now [23][24][25] . Although it seems that our universe is to a very high accuracy Lorentz invariant 23,26 , finding a coherent formulation of Lorentz violating QED seems to be challenging and has generated a very active theoretical debate 21,25,[27][28][29][30][31][32][33][34][35] . In particular from the beginning it was realized 25 that an action of the form (1) generated a Chern Simons term in the effective action for the electromagnetic gauge field of the form 1 2 k µF µν A ν whereF µν = µνρσ F ρσ .…”

Propagation of photons and massive vector mesons between a parity breaking medium and vacuum

“…The general solutions of the equations for the Maxwell-Chern-Simons free quantum field, have been extensively discussed and applied in [72,73] for the massive case and in [14] for the massless case. However, in the light of the present applications it's better to shortly overview this topic.…”

CPT and Lorentz violation effects in hydrogenlike atoms

“…[7,8,9,10,11]), and to study the assumed violation on various high-energy processes [12,13,14,15]. This search also seems quite promising in atomic physics [16,17].…”