A Note on the Radiatively Induced Lorentz and CPT Violated Chern-Simons-like Term in the Extended Quantum Electrodynamics

We show that the ambiguity for the Chern-Simons-like term induced from quantum correction in the extended QED should have nothing to do with the approximation on the exact fermionic propagator, contradictory to the claim in Ref.[19]. Further, we investigate the induced Chern-Simons-like term using the original 't Hooft-Veltman dimensional regularization and reproduce the result obtained by gauge symmetry analysis. This fact demonstrates that the origin of the ambiguity should lie in different choices on regularization schemes.