Exploring Higgs triplet models via vector boson scattering at the LHC

Abstract

We present the results of a study of Higgs triplet boson production arising in the littlest Higgs, left-right symmetric, and Georgi-Machacek models in the ${W}^{\ifmmode\pm\else\textpm\fi{}}{W}^{\ifmmode\pm\else\textpm\fi{}}$, ${W}^{\ifmmode\pm\else\textpm\fi{}}Z$, ${W}^{+}{W}^{\ensuremath{-}}$, and $ZZ$ channels at the LHC. We focus on the ``gold-plated'' purely leptonic decay modes and consider the irreducible electroweak, QCD, and $t$-quark backgrounds, applying a combination of forward-jet tagging, central-jet vetoing, and stringent leptonic cuts to suppress the backgrounds. We find that, given the constraints on the triplet vacuum expectation value (vev), considerable luminosity is required to observe Higgs triplet bosons in vector boson scattering. Observing a Higgs triplet at the LHC is most promising in the Georgi-Machacek model due to a weaker constraint on the triplet vev. In this model, we find that a Higgs triplet boson with a mass of 1.0(1.5) TeV can be observed at the LHC with an integrated luminosity as low as $41(119)\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ in the ${W}^{\ifmmode\pm\else\textpm\fi{}}{W}^{\ifmmode\pm\else\textpm\fi{}}$ channel and as low as $171(474)\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ in the ${W}^{\ifmmode\pm\else\textpm\fi{}}Z$ channel. Observation of Higgs triplet bosons in these channels would help identify the underlying theory.