Lorentz violation in γ-pair production (e + e − → γ γ)

In this paper, we investigate the production process of a photon pair in a regime of quantum electrodynamics, considering the presence of a constant four-vector that defines a privileged direction in spacetime, resulting in Lorentz symmetry violation. We explore Lorentz violation in the context of vectorial nonminimal coupling, where we analyze the modifications introduced by this coupling in the scattering amplitude at the vertex. Moreover, we delve into Lorentz violation with axial-like nonminimal coupling. Both analyses are conducted by examining the constant four-vector of both time-like and space-like types.