Dark matter in inert triplet models

Abstract

We study the inert triplet models, in which the standard model is extended to have a new SUð2Þ L triplet scalar (Y ¼ 0 or 2) with an Z 2 symmetry. We show that the neutral component of the triplet can be a good dark matter candidate. In particular, for the hypercharge Y ¼ 0 triplet model, the WMAP data favors the region where the dark matter mass is around 5.5 TeV, which is also consistent with the direct detection experiments. In contrast, for the Y ¼ 2 model, although dark matter with its mass around 2.8 TeV is allowed by WMAP, it is excluded by the direct detection experiments because the spin-independent cross section is enhanced by the Z-mediated tree-level scattering process.

Discrimination of dark matter models in future experiments

“…In that case, the Higgs boson as well as other SM particles carries information on the DM. In literature, such kind of various particle models have been proposed and their phenomenology have been studied, for example [4,5,6,7,9,10,11,12,13,14,15,16,17].…”

Naturally small Dirac neutrino mass with intermediate SU(2) L multiplet fields

“…In model (f) and (i), an inert scalar doublet η ∼ (1, 2, 1) and a complex inert scalar triplet ∆ ∼ (1, 3, 2) are added [106]. Naively, we expect that the DM candidate is η 0 R or η 0 I in these two models, since ∆ 0 R or ∆ 0 I cannot play the role of DM candidate solely if η does not exist [104]. However, in these two models, a mass splitting…”

“…While for the high mass region, although hard to be test at LHC, most parameter space of this region is in the reach of CTA experiment [99,100]. For model (d) and (h), they employ an inert doublet η ∼ (1, 2, 1) and a real inert scalar triplet ∆ ∼ (1, 3, 0) [101][102][103][104]. Alternatively, the DM candidate could be either η 0 R /η 0 I in the inert doublet η or ∆ 0 in the inert triplet ∆ [105].…”

“…But the scalar triplet ∆ has already excluded by the direct detection experiments [104]. Therefore, these two models could not provide viable DM candidate.…”

Two-loop radiative seesaw model with inert triplet scalar field

“…We discuss bosonic DM candidates η R and ∆ R [64]. Notice here that the DM mass range be less than M W = 80 GeV to satisfy the constraint of the antiproton no excess reported by PAMELA [65] as well as WMAP 5 .…”