LHC phenomenology of a two-Higgs-doublet neutrino mass model

Abstract

We study the LHC search prospects for a model in which the neutrinos obtain Dirac masses from couplings to a second Higgs doublet with tiny vacuum expectation value. The model contains a charged Higgs boson that decays to $\ensuremath{\ell}\ensuremath{\nu}$ with branching fractions controlled by the neutrino masses and mixing angles as measured in neutrino oscillation experiments. The most promising signal is electroweak production of ${H}^{+}{H}^{\ensuremath{-}}$ pairs with decays to $\ensuremath{\ell}{\ensuremath{\ell}}^{\ensuremath{'}}{p}_{T}^{\mathrm{miss}}$, where $\ensuremath{\ell}{\ensuremath{\ell}}^{\ensuremath{'}}={e}^{+}{e}^{\ensuremath{-}}$, ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, and ${e}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\mu}}^{\ensuremath{\mp}}$. We find that a cut on the kinematic variable ${M}_{T2}$ eliminates most of the $t\overline{t}$ and $W$-pair background. Depending on the neutrino mass spectrum and mixing angles, a 100 (300) GeV charged Higgs could be discovered at the LHC with as little as $8\text{ }(24)\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity at 14 TeV $pp$ center-of-mass energy.