Type-II Seesaw Model and Multilepton Signatures at Hadron Colliders

TL;DR

This paper studies multilepton signals from charged Higgs bosons in the Type-II Seesaw model at current and future colliders, identifying potential discovery mass ranges at the LHC and VLHC.

Contribution

It provides a comprehensive analysis of decay modes and multilepton signatures across different $v_{\Delta}$ regimes, extending to 100 TeV colliders.

Findings

Doubly charged Higgs around 375 GeV detectable at LHC

Heavier Higgs up to 630 GeV detectable at high-luminosity LHC or VLHC

Distinctive four and five lepton signatures identified

Abstract

We investigate multilepton signatures, arising from the decays of doubly charged and singly charged Higgs bosons in the Type-II Seesaw model. Depending on the vacuum expectation value of the triplet $v_{\Delta}$, the doubly and singly charged Higgs bosons can decay into a large variety of multi-lepton final states. We explore all possible decay modes corresponding to different regimes of $v_{\Delta}$, that generate distinguishing four and five leptonic signatures. We focus on the 13 TeV Large Hadron Collider (LHC) and further extend the study to a very high energy proton-proton collider (VLHC) with a center-of-mass energy of 100 TeV. We find that a doubly charged Higgs boson of masses around 375 GeV can be discovered at immediate LHC runs. A heavier mass of 630 GeV can instead be discovered at the high-luminosity run of the LHC or at the VLHC with 30 $\rm{fb}^{-1}$.