Trimuon production at the LHC

Abstract

No process without a standard model (SM) background has been observed so far. As a tool in the study of a class of models containing doubly charged vector bileptons, we propose one such process that, violating lepton flavor number conservation, has no contribution from the SM: pp → µ + µ + µ − e − . By carefully isolating the parameters to keep them free, we are able to acquire a notion of how a possible PMNS-like matrix present in the relevant charged current parametrization could affect the observables. We find that an interesting section of the space of parameters can be explored at the current LHC in the specified conditions.

Model-independent constraints on exotic particle masses from lepton decays and the role of interference

“…However, the bound above is derived through constructions that neglect the V U mixing of the U -ll interaction [33][34][35][36][37][38][39][40][41][42][43][44] (an exception is the work in Ref. [22], which takes it into account through a very simplified construction). This unitary mixing matrix is predicted by a skeptical analysis and definition of the interaction form and, for a vector bilepton, cannot be ignored.…”

“…2d) the constraints are strong, demanding M U > 3200 GeV and M U > 6900 GeV, respectively. If there is no interference with extra particles capable of strongly altering this behaviour, this is enough to exclude often used benchmark points or substitute weaker exclusion ranges derived in the LHC phenomenology literature for this particle [22,[33][34][35][36][37][38][39][40][41][42][43][44], which is produced according to assumptions analogous to those contained in the mentioned cases.…”

“…Besides being efficient because of virtually nonexistent SM background, CLFV is also a great prospect for BSM searches because it may be contained in most kinds of new physics models, such as Supersymmetry [12][13][14][15], 2HDM [16][17][18] and 3-3-1 models [19][20][21][22].…”

Challenges for the 3-3-1 models

“…The process with three muons may occur at LHC also, and assuming the only source of this decay is the doubly charged vector it could be discovery at the LHC if its mass is of the order of the 1 TeV [117], see Fig. 8.…”

“…8: pp → 3µ + X considering only SM+U ++ µ . This process has no irreducible background since the SM vertices conserve flavor [117]. double charge were not negligible or/and there are other realistic solutions for the leptonic mixing matrices.…”