Seção de choque dos espalhamentos elétron-pósitron e Bhabha à temperatura finita no contexto de violação da simetria de Lorentz

Abstract

In this work we investigate the effects of the violation of the Lorentz and CPT symmetries on two wellknown processes in quantum electrodynamics, the eletcron-positron process and the Bhabha scattering, and both in the context of finite temperature. The violation mechanism is explicitly implemented via a non-minimal covariant derivative, constructed with a rank-4 background tensor field coupled to the electromagnetic field intensity; while temperature is introduced via the formalism of the thermal field dynamics. Such tree-level inclusions, in addition to reproducing the term in e 4 proportional cross section similar to that obtained from the usual version, also provide us with new vertex contributions proportional to the square of the coupling constant of the violation sector, λ 2 ; in addition to temperature being strongly present as a global factor in the total cross section of the process. Additionally, the conventional cross section resumes under the λ and T boundary conditions tending to zero, as expected.