Stealth dark matter: Dark scalar baryons through the Higgs portal (original) (raw)

Dark matter coupling to electroweak gauge and Higgs bosons: An effective field theory approach

Physics of the Dark Universe, 2013

If dark matter is a new species of particle produced in the early universe as a cold thermal relic (a weakly-interacting massive particle-WIMP), its present abundance, its scattering with matter in direct-detection experiments, its present-day annihilation signature in indirect-detection experiments, and its production and detection at colliders, depend crucially on the WIMP coupling to standard-model (SM) particles. It is usually assumed that the WIMP couples to the SM sector through its interactions with quarks and leptons. In this paper we explore the possibility that the WIMP coupling to the SM sector is via electroweak gauge and Higgs bosons. In the absence of an ultraviolet-complete particle-physics model, we employ effective field theory to describe the WIMP-SM coupling. We consider both scalars and Dirac fermions as possible dark-matter candidates. Starting with an exhaustive list of operators up to dimension 8, we present detailed calculation of dark-matter annihilations to all possible final states, including γγ, γZ, γh, ZZ, Zh, W + W − , hh, and ff , and demonstrate the correlations among them. We compute the mass scale of the effective field theory necessary to obtain the correct dark-matter mass density, and well as the resulting photon line signals. PACS numbers: 98.70.Cq, 95.35.+d, 95.30.Cq, 95.55.Ka, 95.85.Ry

Dark Matter Candidate in a Heavy Higgs Model: Direct Detection Rates

Modern Physics Letters A, 2008

We investigate direct detection rates for Dark Matter candidates arise in a SU(2) L × U(1) Y with an additional doublet Higgs proposed by Barbieri, Hall and Rychkov. We refer this model as 'Heavy Higgs Model'. The Standard Model Higgs mass comes out in this model very heavy adopting the few per cent chance that there is no Higgs boson mass below 200 GeV. The additional Higgs boson develops neither any VEV due to the choice of coefficient of the scalar potential of the model nor it has any coupling with fermions due to the incorporation of a discrete parity symmetry. Thus, the neutral components of the extra doublet are stable and can be considered as probable candidate of Cold Dark Matter. We have made calculations for three different types of Dark Matter experiments, namely, 76 Ge (like GENIUS), DAMA (NaI) and XENON ( 131 Xe). Also demonstrated the annual variation of Dark Matter detection in case of all three detectors considered. PACS: 95.35.+d, 14.80.Bn

Phenomenology of the Hidden SU(2) Vector Dark Matter Model

2021

We investigate the phenomenology of an extension of the Standard Model (SM) by a non-abelian gauge group SU(2)_HS where all SM particles are singlets under this gauge group, and a new scalar representation ϕ that is singlet under SM gauge group and doublet under SU(2)_HS. In this model, the dark matter (DM) candidates are the three mass degenerate dark photons A_i (i=1,2,3) of SU(2)_HS; and the hidden sector interacts with the (SM) particles through the Higgs portal interactions. Consequently, there will be a new CP-even scalar η that could be either heavier or lighter than the SM-like Higgs. By taking into account all theoretical and experimental constraints such as perturbativity, unitarity, vacuum stability, non-SM Higgs decays, DM direct detection, DM relic density, we found viable DM is possible in the range from GeV to TeV. Within the viable parameters space, the both of the triple Higgs coupling and the di-Higgs production at LHC14 could be enhanced or reduced depending on th...

Baryonic Higgs and dark matter

Journal of High Energy Physics, 2021

We discuss the correlation between dark matter and Higgs decays in gauge theories where the dark matter is predicted from anomaly cancellation. In these theories, the Higgs responsible for the breaking of the gauge symmetry generates the mass for the dark matter candidate. We investigate the Higgs decays in the minimal gauge theory for Baryon number. After imposing the dark matter density and direct detection constraints, we find that the new Higgs can have a large branching ratio into two photons or into dark matter. Furthermore, we discuss the production channels and the unique signatures at the Large Hadron Collider.

Gauge-Singlet Vector-Like Fermion Dark Matter, LHC Diphoton Rate, and Direct Detection

Advances in High Energy Physics

We study a gauge-singlet vector-like fermion hidden sector dark matter model, in which the communication between the dark matter and the visible standard model sector is via the Higgs-portal scalar-Higgs mixing and also via a hidden sector scalar with loop-level couplings to two gluons and also to two hypercharge gauge bosons induced by a vector-like quark. We find that the Higgs-portal possibility is stringently constrained to be small by the recent LHC di-Higgs search limits, and the loop induced couplings are important to include. In the model parameter space, we present the dark matter relic density, the dark-matter-nucleon direct detection scattering cross section, the LHC diphoton rate from gluon-gluon fusion, and the theoretical upper bounds on the fermion-scalar couplings from perturbative unitarity.

Hidden Higgs boson at the LHC and light dark matter searches

Physical Review D, 2011

Recent LHC searches have not found a clear signal of the Higgs boson h of the standard model (SM) with three or four families in the mass range m h = 120-600 GeV. If the Higgs had an unexpectedly large invisible branching ratio, the excluded m h regions would shrink. This can be realized in the simplest weakly interacting massive particle dark matter (DM) model, which is the SM plus a real gauge-singlet scalar field D as the DM, via the invisible mode h → DD. Current data allow this decay to occur for D-mass values near, but below, m h /2 and those compatible with the light DM hypothesis. For such D masses, h → DD can dominate the Higgs width depending on m h , and thus sizable portions of the m h exclusion zones in the SM with three or four families may be recovered. Increased luminosity at the LHC may even reveal a Higgs having SM-like visible decays still hiding in the presently disallowed regions. The model also accommodates well the new possible DM hints from CRESST-II and will be further tested by improved data from future DM direct searches.

Direct Detection of Stealth Dark Matter through Electromagnetic Polarizability

We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar baryon dark matter candidate -- "Stealth Dark Matter", that is based on a dark SU(4) confining gauge theory. In the nonrelativistic limit, electromagnetic polarizability proceeds through a dimension-7 interaction leading to a very small scattering cross section for dark matter with weak scale masses. This represents a lower bound on the scattering cross section for composite dark matter theories with electromagnetically charged constituents. We carry out lattice calculations of the polarizability for the lightest baryons in SU(3) and SU(4) gauge theories using the background field method on quenched configurations. We find the polarizabilities of SU(3) and SU(4) to be comparable (within about 50%) normalized to the baryon mass, which is suggestive for extensions to larger SU(N) groups. The resulting scattering cross sect...

Low-mass dark-matter hint from CDMS II, Higgs boson at the LHC, and darkon models

Physical Review D, 2013

The CDMS II experiment has observed three events which may have arisen from weakly interacting massive particle (WIMP) dark matter (DM) with mass of order 9 GeV colliding with nuclei. Although the implied WIMP parameter region seems to be excluded by limits from the XENON experiments, it is interesting that most of this tension can go away if the WIMP-nucleon interaction violates isospin. This motivates us to explore some of the implications for models in which a real gauge-singlet scalar particle, the darkon, serves as the WIMP, taking into account the recent discovery of a Higgs boson at the LHC and Planck determination of the DM relic density. In the simplest scenario, involving only the standard model plus a darkon, the Higgs boson is largely invisible due to its decay into a pair of darkons having the WIMP mass suggested by CDMS II and hence cannot be identified with the one found at the LHC. We find, on the other hand, that a two-Higgs-doublet model supplemented with a darkon has ample parameter space to accommodate well both the new potential DM hint from CDMS II and the Higgs data from the LHC, whether or not the darkon-nucleon interaction conserves isospin.