The fermionic dark matter Higgs portal: an effective field theory approach

We update the parameter space of a singlet Majorana fermion dark matter model, in which the standard particles interact with the dark sector through the mixing of a singlet scalar and the Higgs boson. In this model both the dark matter and the singlet scalar carry lepton number, the latter being a bilepton. The stability of the Majorana fermion is achieved by a supposed Z 2 symmetry. The lepton number symmetry breaking scale, driven by the singlet scalar, is constrained to be within hundreds to thousands of GeV, so as to give a sufficiently abundant Majorana fermion. Relic density, direct detection and invisible Higgs decay are considered in a complementary way, as we contrast our parameter space with the Planck, LUX and LHC bounds. The impacts of the future Higgs self-coupling measurements and of XENON1T detector are also discussed. We find a "narrow" Higgs portal in the sense that large deviations from the standard scalar sector (large mixing and low lepton breaking scale) are very restricted by Higgs data global fit. We perform a systematic study of the allowed parameter space, favored by scalar resonances and degeneracy. One important phenomenological signature of this model is the correlation between the discoveries of a dark matter and a singlet scalar particles. Very light singlet scalars were found disfavored by direct detection, interestingly implying that the Majoron present in our spectrum can hardly be a dark radiation candidate if our scenario addresses the DM issue. This model is very predictive and in the next few years should be completely tested by the experiments.

Section: Jhep09(2015)147supporting

confidence: 56%

“…[25], considering generic scalar, Majorana fermion and vector DM candidates in the effective field theory (EFT) framework. EFT models with Majorana DM were also considered in [13,14,26]. Within EFT approach, the CP-conserving Higgs portal of a fermionic DM is excluded by direct detection search for the DM mass range of 60 GeV-2 TeV.…”

Section: Jhep09(2015)147mentioning

confidence: 99%

Majorana dark matter through a narrow Higgs portal

Dutra

Pires

Silva

2015

“…Modifications of gravity as well as additional matter degrees of freedom are both considered as possible candidates. A particularly simple model contains an additional "dark", i.e., uncharged fermion ψ, that couples to the Higgs field H of the Standard Model through a Higgs-portal interaction [1,2] of the form L HP =λ hψψ ψ H † H.…”

Section: Introductionmentioning

confidence: 99%

Asymptotic safety in the dark

Eichhorn¹,

Held²,

Griend

2018

We explore the Renormalization Group flow of massive uncharged fermions -a candidate for dark matter -coupled to a scalar field through a Higgs portal. We find that fermionic fluctuations can lower the bound on the scalar mass that arises from vacuum stability. Further, we discuss that despite the perturbative nonrenormalizability of the model, it could be ultraviolet complete at an asymptotically safe fixed point. In our approximation, this simple model exhibits two mechanisms for asymptotic safety: a balance of fermionic and bosonic fluctuations generates a fixed point in the scalar self-interaction; asymptotic safety in the portal coupling is triggered through a balance of canonical scaling and quantum fluctuations. As a consequence of asymptotic safety in the dark sector, the low-energy value of the portal coupling could become a function of the dark fermion mass and the scalar mass, thereby reducing the viable parameter space of the model.

“…After electroweak symmetry breaking, this operator generally gives rise to both scalar and pseudoscalar contributions to DM annihilation, h →ψψ, and DM-nucleon scattering [14,53]. The pseudoscalar one can alleviate the v 2 rel suppression in σannv rel , but yields a tiny effect on the DM-nucleon cross-section.…”

Section: Spin-3/2 Dark Mattermentioning

confidence: 99%

Two-Higgs-doublet-portal dark-matter models in light of direct search and LHC data

Chang

Tandean

2017

We explore simple Higgs-portal models of dark matter (DM) with spin 1/2, 3/2, and 1, respectively, applying to them constraints from the LUX and PandaX-II direct detection experiments and from LHC measurements on the 125-GeV Higgs boson. With only one Higgs doublet, we find that the spin-1/2 DM having a purely scalar effective coupling to the doublet is viable only in a narrow range of mass near the Higgs pole, whereas the vector DM is still allowed if its mass is also close to the Higgs pole or exceeds 1.4 TeV, both in line with earlier analyses. Moreover, the spin-3/2 DM is in a roughly similar situation to the spin-1/2 DM, but has surviving parameter space which is even more restricted. We also consider the two-Higgs-doublet extension of each of the preceding models, assuming that the expanded Yukawa sector is that of the two-Higgs-doublet model of type II. We show that in these two-Higgs-doublet-portal models significant portions of the DM mass regions excluded in the simplest scenarios by direct search bounds can be reclaimed due to suppression of the effective DM interactions with nucleons at some ratios of the CP -even Higgs bosons' couplings to the up and down quarks. The regained parameter space contains areas which can yield a DM-nucleon scattering cross-section that is far less than its current experimental limit or even goes below the neutrino-background floor.