Possibility of early Higgs boson discovery in nonminimal Higgs sectors

Abstract

Particle physics models with more than one Higgs boson occur in many frameworks for physics beyond the standard model, including supersymmetry, technicolor, composite Higgs, and ``little Higgs'' models. If the Higgs sector contains couplings stronger than electroweak gauge couplings, there will be heavy Higgs particles that decay to lighter Higgs particles plus heavy particles such as $W$, $Z$, and $t$. This motivates searches for final states involving multiple $W$, $Z$, $t$, and $\overline{b}b$ pairs. A two Higgs doublet model with custodial symmetry is a useful simplified model to describe many of these signals. The model can be parameterized by the physical Higgs masses and the mixing angles $\ensuremath{\alpha}$ and $\ensuremath{\beta}$, so discovery or exclusion in this parameter space has a straightforward physical interpretation. We illustrate this with a detailed analysis of the process $gg\ensuremath{\rightarrow}A$ followed by $A\ensuremath{\rightarrow}hZ$ and $h\ensuremath{\rightarrow}WW$. For ${m}_{A}\ensuremath{\simeq}330\text{ }\text{ }\mathrm{GeV}$, ${m}_{h}\ensuremath{\simeq}200\text{ }\text{ }\mathrm{GeV}$ we can get a $4.5\ensuremath{\sigma}$ signal with $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity at the Large Hadron Collider.