Freeze-in Dark Matter via Light Dirac Neutrino Portal

Abstract

We propose a scenario where dark matter (DM) can be generated non-thermally due to the presence of a light Dirac neutrino portal between the standard model (SM) and dark sector particles. The SM is minimally extended by three right handed neutrinos (${\nu }_R$), a Dirac fermion DM candidate ($\psi$) and a complex scalar ($\varphi$), transforming non-trivially under an unbroken ${\mathbb{Z}}_4$ symmetry while being singlets under the SM gauge group. While DM and ${\nu }_R$ couplings are considered to be tiny in order to be in the non-thermal or freeze-in regime, $\varphi$ can be produced either thermally or non-thermally depending upon the strength of its Higgs portal coupling. We consider both these possibilities and find out the resulting DM abundance via freeze-in mechanism to constrain the model parameters in the light of Planck 2018 data. Since the interactions producing DM also produces relativistic ${\nu }_R$, we check the enhanced contribution to the effective relativistic degrees of freedom $\Delta {\mathrm{N}}_{\mathrm{eff}}$ in view of existing bounds as well as future sensitivities. We also check the stringent constraints on free-streaming length of such freeze-in DM from structure formation requirements. Such constraints can rule out DM mass all the way up to $\mathcal{O}(100\mathrm{keV})$ keeping the $\Delta {\mathrm{N}}_{\mathrm{eff}}\le \mathcal{O}(10^{-3})$, out of reach from near future experiments. Possible extensions of this minimal model can lead to observable $\Delta {\mathrm{N}}_{\mathrm{eff}}$ which can be probed at next generation experiments.

48 pages, 10 captioned figures, matches version accepted for publication in Phys. Rev. D

References in corpus (24)

• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• Relic neutrino decoupling with flavour oscillations revisited
• SPT-3G: A Next-Generation Cosmic Microwave Background Polarization Experiment on the South Pole Telescope
• A lower bound on the mass of Dark Matter particles
• The real singlet scalar dark matter model
• How warm are non-thermal relics? Lyman-$\alpha$ bounds on out-of-equilibrium dark matter
• Constraints on the properties of warm dark matter using the satellite galaxies of the Milky Way
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: The Most General Case
• Lyman-$\alpha$ constraints on freeze-in and superWIMPs
• Search for invisible Higgs-boson decays in events with vector-boson fusion signatures using 139 ${\text{fb}}^{-1}$ of proton-proton data recorded by the ATLAS experiment
• Search for invisible decays of the Higgs boson produced via vector boson fusion in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Dirac neutrinos and $N_{\mathrm{eff}}$
• Freeze-in Production of Sterile Neutrino Dark Matter in U(1)${}_{\mathrm{B}-\mathrm{L}}$ Model
• Nonthermal Two Component Dark Matter Model for Fermi-LAT $\gamma$-ray excess and 3.55 keV X-ray Line
• Dirac neutrinos and $N_{\mathrm{eff}}$ II: the freeze-in case
• Type II Dirac Seesaw with Observable $\Delta N_{\mathrm{eff}}$ in the light of W-mass Anomaly
• Neutrino non-standard interactions meet precision measurements of $N_{\mathrm{eff}}$
• Light Dirac neutrino portal dark matter with observable $\Delta N_{\mathrm{eff}}$
• Non-thermal leptogenesis and UV freeze-in of dark matter: impact of inflationary reheating
• Dark Matter Abundance from Sequential Freeze-in Mechanism
• Calculation of Momentum Distribution Function of a Non-thermal Fermionic Dark Matter
• Unraveling the Dirac Neutrino with Cosmological and Terrestrial Detectors
• Observing Left-Right Symmetry in the Cosmic Microwave Background
• Low scale Dirac leptogenesis and dark matter with observable $\Delta N_{\mathrm{eff}}$

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• CMB signature of non-thermal Dark Matter produced from self-interacting dark sector
• CDF-II W boson mass in the Dirac Scotogenic model
• FIMP Dark Matter from Flavon Portals
• Cosmological Probes of Lepton Parity Freeze-in Dark Matter: $\Delta N_{\mathrm{eff}}$ & Gravitational Waves