The case for mixed dark matter from sterile neutrinos

Abstract

Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via standard model charged and neutral current vertices under a minimal set of assumptions: i) the mass basis contains a hierarchy of heavy neutrinos, ii) these have very small mixing angles with the active (flavor) neutrinos, iii) standard model particles, including light (active-like) neutrinos are in thermal equilibrium. The same weak interaction processes that produce active-like neutrinos also produce the heavier species. We introduce the kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. We identify processes in which finite temperature collective excitations lead to the production of the heavy species. As a specific example, we consider the production of heavy neutrinos from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from "kinematic entanglement" and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime $\tau >1/H_0$ freeze out of local thermal equilibrium, and \emph{conjecture} that those with lifetimes $\tau \ll 1/H_0$ may undergo cascade decay into lighter DM candidates and/or inject non-LTE neutrinos into the cosmic neutrino background. We provide a comparison with non-resonant production via active-sterile mixing.

62 pages, 17 figs, expanded discussions, matches published version

References in corpus (60)

• Big-Bang Nucleosynthesis
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• The equation of state in (2+1)-flavor QCD
• Equation of state and QCD transition at finite temperature
• Neutrinos and Collider Physics
• Light Sterile Neutrinos: A White Paper
• Dark-matter sterile neutrinos in models with a gauge singlet in the Higgs sector
• Too Big to Fail in the Local Group
• Signatures for Majorana neutrinos at hadron colliders
• Is there a "too big to fail" problem in the field?
• Opening a new window for warm dark matter
• Sterile neutrino dark matter as a consequence of nuMSM-induced lepton asymmetry
• Discovery of a 3.5 keV line in the Galactic Center and a Critical Look at the Origin of the Line Across Astronomical Targets
• Direct Bounds on Electroweak Scale Pseudo-Dirac Neutrinos from $\sqrt{s}=8$ TeV LHC Data
• Resonantly-Produced 7 keV Sterile Neutrino Dark Matter Models and the Properties of Milky Way Satellites
• Unified explanation of the $eejj$, diboson and dijet resonances at the LHC
• Prospects of Heavy Neutrino Searches at Future Lepton Colliders
• On the hadronic contribution to sterile neutrino production
• Heavy neutrinos and the $pp\to lljj$ CMS data
• Sensitivity of Next-Generation Tritium Beta-Decay Experiments for keV-Scale Sterile Neutrinos
• Search for a Light Sterile Neutrino at Daya Bay
• Sterile neutrino dark matter: A tale of weak interactions in the strong coupling epoch
• The emptiness of voids: yet another over-abundance problem for the LCDM model
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: Basic Concepts and Subtle Features
• Strong Upper Limits on Sterile Neutrino Warm Dark Matter
• The phase space density of fermionic dark matter haloes
• Clustering properties of a sterile neutrino dark matter candidate
• Improved determination of sterile neutrino dark matter spectrum
• Multiple dark matter scenarios from ubiquitous stringy throats
• Small-scale structure formation properties of chilled sterile neutrinos as dark matter
• Diluted equilibrium sterile neutrino dark matter
• Sterile neutrinos as subdominant warm dark matter
• Improved Limits on Sterile Neutrino Dark Matter using Full-Sky Fermi Gamma-Ray Burst Monitor Data
• A New Direction in Dark-Matter Complementarity: Dark-Matter Decay as a Complementary Probe of Multi-Component Dark Sectors
• Small scale aspects of warm dark matter : power spectra and acoustic oscillations
• Right-handed neutrino production rate at T > 160 GeV
• The pion quasiparticle in the low-temperature phase of QCD
• Effective Field Theory out of Equilibrium: Brownian quantum fields
• Dodelson-Widrow Production of Sterile Neutrino Dark Matter with Non-Trivial Initial Abundance
• Oscillation of heavy sterile neutrino in decay of $B\to \mu e\pi$
• New limits on radiative sterile neutrino decays from a search for single photons in neutrino interactions
• A Search for a keV Signature of Radiatively Decaying Dark Matter with Suzaku XIS Observations of the X-ray Diffuse Background
• A Fresh Look at keV Sterile Neutrino Dark Matter from Frozen-In Scalars
• Nearly degenerate heavy sterile neutrinos in cascade decay: mixing and oscillations
• Cosmological Implications of Light Sterile Neutrinos produced after the QCD Phase Transition
• The dark matter transfer function: free streaming, particle statistics and memory of gravitational clustering
• Free streaming in mixed dark matter
• From Quark-Gluon Universe to Neutrino Decoupling: 200<T<2MeV
• MeV-Scale Dark Matter Deep Underground
• Search for Heavy Right-Handed Neutrinos at the LHC and Beyond in the Same-Sign Same-Flavor Leptons Final State
• Reply to Two Comments on "Dark matter searches going bananas the contribution of Potassium (and Chlorine) to the 3.5 keV line"
• Right-handed neutrinos and the 2 TeV $W^{\prime }$ boson
• Cosmology and Neutrino Properties
• Constraining Sterile Neutrinos Using Reactor Neutrino Experiments
• The LSND/MiniBooNe excess events and heavy neutrino from muon and kaon decays
• Sterile Neutrino Dark Matter Production in the Neutrino-phillic Two Higgs Doublet Model
• Space-time evolution of heavy sterile neutrinos in cascade decays
• Electromagnetic effects in the pion dispersion relation at finite temperature
• Structure formation in warm dark matter cosmologies: Top-Bottom Upside-Down
• Pion masses at finite temperature

Cited by in corpus (8)

• Sterile Neutrino Dark Matter
• A White Paper on keV Sterile Neutrino Dark Matter
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: The Most General Case
• Dodelson-Widrow Production of Sterile Neutrino Dark Matter with Non-Trivial Initial Abundance
• Sterile neutrino Dark Matter production from scalar decay in a thermal bath
• Production of heavy sterile neutrinos from vector boson decay at electroweak temperatures
• Thermal effects in freeze-in neutrino dark matter production
• Testable dark matter solution within the seesaw mechanism