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

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-s1 that can survive the present and even the future experiments: (1) the Higgs resonance region with M-s1 similar to M-h/2, (2) the Higgs region with M-s1 similar to M-h, and (3) the coannihilation region with M-s2 similar to M-s1. 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 sigma significance with an integrated luminosity of 100 fb(-1).