Espalhamento fóton-fóton: ambiguidades e seção de choque

Abstract

In this paper we calculate the scattering cross section in a regularization independent fashion, through Implicit Regulzarization scheme, and compare our result with previous analyses. These calculations possess many interesting physical and mathematical features. It is characterized by a finite total amplitude, as required by gauge invariance, which nevertheless needs a regularization scheme in the intermediate steps which brings in intrinsic ambiguities. We show that such ambiguities are fixed on momentum routing invariance grounds which in turn are related to surface terms - which appear by the finite difference of two integrals with the same level of divergence - and gauge symmetry.