Phenomenology of a lepton triplet

TL;DR

This paper develops a comprehensive phenomenological model for a lepton triplet with hypercharge ±1, predicting exotic leptons like a doubly charged lepton and heavy neutrinos, and explores their detectability at the LHC.

Contribution

It introduces the most general model involving a lepton triplet with hypercharge ±1, detailing its phenomenology and potential experimental signatures at colliders and low-energy experiments.

Findings

Exotic leptons could be observable at the LHC with sufficient luminosity.

Model predicts flavor-changing neutral currents affecting rare muon decays.

Decay channels of exotic leptons are thoroughly described across parameter space.

Abstract

The most general phenomenological model involving a lepton triplet with hypercharge $\pm 1$ is constructed. A distinctive feature of this model is the prediction of a doubly charged lepton, and a new heavy Dirac neutrino. We study the phenomenology of these exotic leptons in both low-energy experiments and at the LHC. The model predicts FCNC processes such as rare muon decays, which are studied in detail in order to constrain the model parameters. All the decay channels of the exotic leptons are described for a wide range of parameters. It is found that, if the mixing parameters between the exotic and light leptons are not too small ($>10^{-6}$), then they can be observable to a $3-5\sigma$ statistical significance at the 7 TeV LHC with 10-50 fb$^{-1}$ luminosity for a 400 GeV mass, and 14 TeV with 100-300 fb$^{-1}$ luminosity for a 800 GeV mass.