Gauge invariance and the Pauli-Villars regulator in Lorentz- and CPT-violating electrodynamics

Jul, 2004
7 pages
Published in:
  • Phys.Rev.D 70 (2004) 101701
e-Print:
Report number:
  • IUHET-473

Citations per year

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Abstract:
We examine the nonperturbative structure of the radiatively induced Chern-Simons term in a Lorentz- and CPT-violating modification of QED. Although the coefficient of the induced Chern-Simons term is in general undetermined, the nonperturbative theory appears to generate a definite value. However, the CPT-even radiative corrections in this same formulation of the theory generally break gauge invariance. We show that gauge invariance may yet be preserved through the use of a Pauli-Villars regulator, and, contrary to earlier expectations, this regulator does not necessarily give rise to a vanishing Chern-Simons term. Instead, two possible values of the Chern-Simons coefficient are allowed, one zero and one nonzero. This formulation of the theory therefore allows the coefficient to vanish naturally, in agreement with experimental observations.
  • 11.30.Er
  • 11.15.Tk
  • 11.30.Cp
  • 11.10.Gh
  • quantum electrodynamics
  • fermion: chiral
  • Chern-Simons term: induced
  • fermion: propagator
  • invariance: gauge
  • perturbation theory: higher-order