Non-Leptonic Decays of Bileptons

TL;DR

This paper analyzes the decay modes of doubly-charged bilepton gauge bosons in specific models, highlighting non-leptonic decay channels and their potential observability at future high-energy colliders.

Contribution

It provides a detailed phenomenological analysis of non-leptonic bilepton decays, including benchmark scenarios and collider prospects, extending previous leptonic decay studies.

Findings

Non-leptonic decays can significantly reduce leptonic decay rates.

Future 100 TeV colliders could observe signals of bileptons.

Analysis suggests collider reach depends on model parameters.

Abstract

We provide a detailed analysis of the decays of doubly-charged bilepton gauge bosons $Y^{\pm\pm}$, as predicted in models based on a $SU(3)_C\times SU(3)_L\times U(1)_X$ symmetry. In addition to the decay modes into same-sign lepton pairs, which were already investigated in scenarios wherein each branching ratio was about one third, there are, depending on the mass spectrum, possible non-leptonic decays which reduce the leptonic rates. These non-leptonic decays are typically into a light quark (antiquark) and a heavy TeV-scale antiquark (quark), which carries double lepton number and decays via virtual bileptons. We choose two benchmark points to represent the particle spectrum and present a phenomenological analysis of such decays. We find that, while the LHC statistics are too low, even in the high-luminosity phase, they can lead to a visible signal at a future 100 TeV hadron collider (FCC-$hh$). A more exhaustive exploration with a rigorous inclusion of tagging efficiencies, detector simulations and higher-order corrections to the partonic cross section, aiming at assessing the reach of LHC and FCC-$hh$ for bileptons as a function of the model parameters, as well as a recast of four-top searches in terms of the bilepton model, are deferred to future work.