Testing the type II radiative seesaw model: From dark matter detection to LHC signatures

Abstract

We analyze the testability of the type II radiative seesaw in which neutrino mass and dark matter (DM) are related at one-loop level. Under the constraints from DM relic density, direct and indirect detection, and invisible Higgs decays, we find three possible regions of DM mass ${M}_{{s}_{1}}$ that can survive the present and even the future experiments: (1) the Higgs resonance region with ${M}_{{s}_{1}}\ensuremath{\sim}{M}_{h}/2$, (2) the Higgs region with ${M}_{{s}_{1}}\ensuremath{\sim}{M}_{h}$, and (3) the coannihilation region with ${M}_{{s}_{2}}\ensuremath{\sim}{M}_{{s}_{1}}$. Here ${s}_{1,2}$ are two scalar singlets with the lighter ${s}_{1}$ being the DM candidate. Based on DM properties and direct collider constraints, we choose three benchmark points to illustrate the testability of this model at the LHC. We perform a detailed simulation of the four-lepton and trilepton signatures at 13(14) TeV LHC. While both signatures are found to be promising at all benchmark points, the trilepton one is even better: it is possible to reach the $5\ensuremath{\sigma}$ significance with an integrated luminosity of $100\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$.