Constraining the Georgi-Machacek Model with a Light Higgs

TL;DR

This paper explores the parameter space of the Georgi-Machacek model with a light Higgs, incorporating various theoretical and experimental constraints, and identifies viable regions that align with current collider bounds.

Contribution

It provides a comprehensive analysis of the light Higgs scenario in the GM model considering recent experimental bounds, highlighting viable parameter regions.

Findings

Identified parameter space where the light Higgs is consistent with constraints.

Showed that current bounds still allow significant viable regions.

Predicted future analyses will further tighten these regions.

Abstract

In this work, we investigate the viability of a light Higgs ($\eta$) scenario in the Georgi-Machacek (GM) model, where we consider all theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs di-photon and undetermined decays and the Higgs total decay width. In addition, we consider more recent experimental bounds from the searches for doubly-charged Higgs bosons in the VBF channel $H_{5}^{++}\rightarrow W^{+}W^{+}$, Drell-Yan production of a neutral Higgs boson $pp\rightarrow H_{5}^{0}(\gamma\gamma)H_{5}^{+}$, and for the light scalars at LEP $e^{-}e^{+}\rightarrow Z\eta$, and at ATLAS and CMS in different final states such as $pp\rightarrow\eta\rightarrow2\gamma$ and $pp\rightarrow h\rightarrow\eta\eta\rightarrow4\gamma,2\mu2\tau,2\mu2b,2\tau2b$. By combining these bounds together, we found a parameter space region that is significant as the case of the SM-like Higgs to be the light CP-even eigenstate, and this part of the parameter space would be tightened by the coming analyses.