Modelos de branas em (5+1) dimensões e o espectro dos leptóns carregados

Abstract

This manuscript is concerned with a mechanism for explaining the mass spectrum of the charged leptons within (5 + 1)-dimensional braneworlds. As a preliminary objective, new two co-dimensional thick braneworlds ought to be proposed and investigated. By considering a twofold-warp factor constructed from two intersecting warp factors and scalar fields that generates the extra dimension defect, an alternative bulk configuration is examined. With the brane localization thus driven by two crossing scalar fields, the possible solvable models obtained from such a two co-dimensional setup are systematically discussed. The obtained solutions are classified into two subsets, string and intersecting-like. The intersecting-like models are sorted in six different models organized into two subsets for which some of their physical properties are evaluated. For models I and II , in the first subset, Einstein equation solutions are rigidly defined, up to some arbitrary constant. For models III , IV , V and V I , in the second subset, an additional degree of freedom not constrained by Einstein equations is admitted. For all intersecting-like models, gravity and standard matter fields are shown to be localized in the vicinity of the brane. Finally, by studying the zero modes of leptons, which are localized by the inclusion of a non-trivial gauge field, over asymmetric versions of the classified braneworlds, one is able to model the masses of the electron, muon and tauon based on two parameters: the gauge field strength and the ratio between the sizes of the co-dimensions.