Constraining the Georgi-Machacek Model with a Light Higgs

Abstract

In this work, we investigate the viability of a light Higgs ($η$) 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 $pp\rightarrow H_{5}^{0}(γγ)H_{5}^{+}$, and for the light scalars at LEP $e^{-}e^{+}\rightarrow Zη$, and at ATLAS and CMS in different final states such as $pp\rightarrowη\rightarrow2γ$ and $pp\rightarrow h\rightarrowηη\rightarrow4γ,2\mu2τ,2\mu2b,2\tau2b$. 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.