Dark matter, singlet extensions of the nuMSM, and symmetries

Abstract

We consider an extension of the nuMSM in which sterile neutrino masses originate from the VEV of a Higgs singlet phi and dark matter is produced through the decays of phi rather than through active-sterile neutrino mixing. This model, which we refer to as the nuNMSM, can readily satisfy or escape the constraints on warm dark matter from the Lyman-alpha forest and other small scale structure. However, it requires a particular hierarchy of Majorana masses and Yukawa couplings without an obvious origin. We show that the hierarchical parameters of the nuNMSM can arise from symmetries broken at or near the Planck scale for two specific examples of this model: one in which phi helps stabilize the electroweak vacuum through a scalar threshold effect and one in which phi is a light inflaton. Both examples require a complex phi and have several experimental signatures that are distinct from the nuMSM. These signatures include additional dark radiation that is relativistic at both primordial nucleosynthesis and CMB decoupling and, for the former, a large invisible branching ratio of the Higgs.

22 pages, 3 tables. v2: Discussion clarified and references added. Matches published version

References in corpus (25)

• The Standard Model Higgs boson as the inflaton
• Higgs mass and vacuum stability in the Standard Model at NNLO
• Higgs inflation: consistency and generalisations
• Sterile neutrinos, dark matter, and the pulsar velocities in models with a Higgs singlet
• Conformal Symmetry and the Standard Model
• A possible symmetry of the $\nu$MSM
• A lower bound on the mass of Dark Matter particles
• Sterile Neutrinos as the Origin of Dark and Baryonic Matter
• The nuMSM, leptonic asymmetries, and properties of singlet fermions
• Opening a new window for warm dark matter
• Sterile neutrino dark matter as a consequence of nuMSM-induced lepton asymmetry
• Unitarizing Higgs Inflation
• Light Sterile Neutrinos: Models and Phenomenology
• Realistic sterile neutrino dark matter with keV mass does not contradict cosmological bounds
• Is the resonance at 125 GeV the Higgs boson?
• Warm Dark Matter in Low Scale Left-Right Theory
• (Non-)Abelian discrete anomalies
• Baryon Asymmetry of the Universe in the NuMSM
• Gamma-Rays from Decaying Dark Matter
• Soft L_e-L_mu-L_tau flavour symmetry breaking and sterile neutrino keV Dark Matter
• Continuous Global Symmetries and Hyperweak Interactions in String Compactifications
• Constraining Warm Dark Matter using QSO gravitational lensing
• Neutrinos, Axions and Conformal Symmetry
• Anomalies of Discrete Symmetries and Gauge Coupling Unification
• Inflaton mass in the nuMSM inflation

Cited by in corpus (7)

• A facility to Search for Hidden Particles at the CERN SPS: the SHiP physics case
• Why should we care about the top quark Yukawa coupling?
• keV Neutrino Model Building
• Sterile Neutrino Dark Matter from Freeze-In
• Neutrino Masses and Higgs Vacuum Stability
• Influence of a keV sterile neutrino on neutrino-less double beta decay -- how things changed in the recent years
• Common origin of reactor and sterile neutrino mixing