Phenomenology of the doubly-charged vector bilepton

Abstract

The Standard Model stands as the first established, complete (gravity aside), fundamental theory of nature. In the other hand, it is unable to account for some universal observations -- besides possessing a number of undesirable characteristics. Thus, there is a pressing need for new physics, which, in the high energy realm, usually imply new particles. In this thesis, we delve into one such particle: the doubly-charged vector bilepton. This particle is a singular feature of Beyond the Standard Model theories and its phenomenology is still incipient. We focus, in particular, on its power as a mediator of Charged Lepton Flavour Mediation, a type of process which, in turn, may represent a smoking gun with respect to its discovery or constraining of its parameters. Such processes have not been skeptically explored, and the lepton mixing in their interaction with the $U^{\pm \pm}$ not been properly focused on. The first step we take is investigating what bounds an LHC trimuon process may impose on the parameter space of this particle. The results motivate us to look for alternative experimental sources of limits. The seven 3-body lepton decay channels delivered a great prospect, and we perform a detailed, model independent analysis of what they can imply for the $U^{\pm \pm}$ and other two exotic species. Special attention is paid to occurring interferences between new contributions. Finally, we proceed to construct a thorough analysis of the evolution of couplings in the Minimal 3-3-1 Model, the main theory incorporating a vector bilepton, examining how it is threatened by Landau poles in its abelian coupling. We explicitly obtain the 1-loop contributions of exotic particles to the runnings, finding that the perturbative regime of the model is in fact considerably larger than conventionally assumed.