Light Dirac neutrino portal dark matter with observable $\Delta N_{\mathrm{eff}}$

Abstract

We propose a Dirac neutrino portal dark matter scenario by minimally extending the particle content of the Standard Model (SM) with three right handed neutrinos (${\nu }_R$), a Dirac fermion dark matter candidate ($\psi$) and a complex scalar ($\varphi$), all of which are singlets under the SM gauge group. An additional ${\mathbb{Z}}_4$ symmetry has been introduced for the stability of dark matter candidate $\psi$ and also ensuring the Dirac nature of light neutrinos at the same time. Both the right handed neutrinos and the dark matter thermalise with the SM plasma due to a new Yukawa interaction involving ${\nu }_R$, $\psi$ and $\varphi$ while the latter maintains thermal contact via the Higgs portal interaction. The decoupling of ${\nu }_R$ occurs when $\varphi$ loses its kinetic equilibrium with the SM plasma and thereafter all three ${\mathbb{Z}}_4$ charged particles form an equilibrium among themselves with a temperature $T_{{\nu }_R}$. The dark matter candidate $\psi$ finally freezes out within the dark sector and preserves its relic abundance. We have found that in the present scenario, some portion of low mass dark matter ($M_{\psi }\lesssim 10$ GeV) is already excluded by the Planck 2018 data for keeping ${\nu }_R$s in the thermal bath below a temperature of 600 MeV and thereby producing an excess contribution to $N_{\mathrm{eff}}$. The next generation experiments like CMB-S4, SPT-3G etc. will have the required sensitivities to probe the entire model parameter space of this minimal scenario, especially the low mass range of $\psi$ where direct detection experiments are still not capable enough for detection.

39 pages, 7 figures, 1 table, a new discussion related to the decay of $\varphi$ has been added in Appendix A, new figures are added, new references are added, conclusion remains unchanged, version accepted for publication in JCAP

References in corpus (27)

• Dark Matter Results from First 98.7-day Data of PandaX-II Experiment
• micrOMEGAs4.1: two dark matter candidates
• CMB-S4 Science Case, Reference Design, and Project Plan
• DARWIN: towards the ultimate dark matter detector
• Relic neutrino decoupling with flavour oscillations revisited
• SPT-3G: A Next-Generation Cosmic Microwave Background Polarization Experiment on the South Pole Telescope
• Low-Mass Dark Matter Search with CDMSlite
• On Effective Degrees of Freedom in the Early Universe
• BBN And The CMB Constrain Neutrino Coupled Light WIMPs
• Pathways to Naturally Small Dirac Neutrino Masses
• The real singlet scalar dark matter model
• A New Two Higgs Doublet Model
• Two-loop Dirac neutrino mass and WIMP dark matter
• A(4) Flavor Symmetry Model for Dirac-Neutrinos and Sizable U(e3)
• Dirac neutrinos and $N_{\mathrm{eff}}$
• Generalized Bottom-Tau unification, neutrino oscillations and dark matter: predictions from a lepton quarticity flavor approach
• Dirac neutrinos and $N_{\mathrm{eff}}$ II: the freeze-in case
• LHC phenomenology of a two-Higgs-doublet neutrino mass model
• Dark Matter Through the Neutrino Portal
• Radiative Left-Right Dirac Neutrino Mass
• Common Origin of Neutrino Mass, Dark Matter and Dirac Leptogenesis
• Neutrino non-standard interactions meet precision measurements of $N_{\mathrm{eff}}$
• Simplest Radiative Dirac Neutrino Mass Models
• Feeble neutrino portal dark matter at neutrino detectors
• Light Sterile Neutrino and Dark Matter in Left-Right Symmetric Models Without Higgs Bidoublet
• Observable Lepton Number Violation with Predominantly Dirac Nature of Active Neutrinos
• Observing Left-Right Symmetry in the Cosmic Microwave Background

Cited by in corpus (21)

• Self-interacting Dark Matter via Right Handed Neutrino Portal
• Dark matter produced from right-handed neutrinos
• Freeze-in Dark Matter via Light Dirac Neutrino Portal
• Concealing Dirac neutrinos from cosmic microwave background
• Long lived inert Higgs in fast expanding universe and its imprint on cosmic microwave background
• Dark Matter and $(g-2{)}_{\mu ,e}$ in radiative Dirac neutrino mass models
• Affleck-Dine Cogenesis of Baryon and Dark Matter
• Collider and CMB complementarity of leptophilic dark matter with light Dirac neutrinos
• Effective neutrino number shift from keV-vacuum neutrinophilic 2HDM
• Time-delayed neutrino emission from supernovae as a probe of dark matter-neutrino interactions
• $(g-2{)}_{e,\mu }$ and strongly interacting dark matter with collider implications
• Freeze-In of radiative keV-scale neutrino dark matter from a new $\text{U}(1{)}_{\text{B-L}}$
• CDF-II W boson mass in the Dirac Scotogenic model
• Sterile Neutrino Portal Dark Matter in $\nu$THDM
• Anomaly-free Abelian gauge symmetries with Dirac seesaws
• Dark matter freeze-in via a light fermion mediator: forbidden decay and scattering
• Imprints of MeV Scale Hidden Dark Sector at Planck Data
• Spontaneously stabilised dark matter from a fermiophobic $U(1{)}^{\prime }$ gauge symmetry
• Phenomenology of Dirac neutrino EFTs up to dimension six
• Unified Origin of Dirac Neutrino and Asymmetric Dark Matter Masses via a Dirac-Type Leptogenesis
• Neutrino flavor mixing with approximate $\mu$-$\tau$ symmetry within the low-scale minimal linear seesaw model