Searches of exotic Higgs bosons in general mass spectra of the Georgi-Machacek model at the LHC

TL;DR

This paper explores the possible mass spectra of exotic Higgs bosons in the Georgi-Machacek model, analyzing their decay channels and detection prospects at current and future colliders, while ensuring consistency with theoretical and experimental constraints.

Contribution

It derives the most general viable mass spectra for exotic Higgs bosons in the Georgi-Machacek model, including decay modes and collider detection strategies, under various constraints.

Findings

Identified viable mass spectra consistent with constraints.

Computed branching ratios for cascade decay channels.

Evaluated detection prospects at 14-TeV and 100-TeV colliders.

Abstract

We derive the most general sets of viable mass spectra of the exotic Higgs bosons in the Georgi-Machacek model that are consistent with the theoretical constraints of vacuum stability and perturbative unitarity and the experimental constraints of electroweak precision observables, $Zb \bar b$ coupling and Higgs boson signal strengths. Branching ratios of various cascade decay channels of the doubly-charged Higgs boson in the ${\bf 5}$ representation, the singly-charged Higgs boson in ${\bf 3}$, and the singlet Higgs boson are further computed. As one of the most promising channels for discovering the model, we study the prospects for detecting the doubly-charged Higgs boson that is produced via the vector boson fusion process and decays into final states containing a pair of same-sign leptons at the 14-TeV LHC and a 100-TeV future $pp$ collider. For this purpose, we evaluate acceptance times efficiency for signals of the doubly-charged Higgs boson with general viable mass spectra and compare it with the standard model background estimates.