Long lived inert Higgs in fast expanding universe and its imprint on cosmic microwave background

Abstract

Presence of any extra radiation energy density at the time of cosmic microwave background formation can significantly impact the measurement of the effective relativistic neutrino degrees of freedom or $\mathrm{\Delta }{\mathrm{N}}_{\mathrm{eff}}$ which is very precisely measured by the Planck collaboration. Here, we propose a scenario where a long lived inert scalar, which is very weakly coupled to dark sector, decays to a fermion dark matter via freeze-in mechanism plus standard model neutrinos at very low temperature $(T<T_{\mathrm{BBN}})$. We explore this model in the fast expanding universe, where it is assumed that the early epoch $(T>T_{\mathrm{BBN}})$ of the universe is dominated by a non-standard species $\Phi$ instead of the standard radiation. In this non-standard cosmological picture, such late time decay of the inert scalar can inject some entropy to the neutrino sector after it decouples from the thermal bath and this will make substantial contribution to $\mathrm{\Delta }{\mathrm{N}}_{\mathrm{eff}}$. Besides, in this scenario, the new contribution to $\Delta N_{\mathrm{eff}}$ is highly correlated with the dark matter sector. Thus, one can explore such feebly interacting dark matter particles (FIMP) by the precise measurement of $\Delta N_{\mathrm{eff}}$ using the current (Planck2018) and forthcoming (CMB-S4 \& SPT3G) experiments.

31 pages, 5 figures, 2 tables, Version accepted for publication in PRD

References in corpus (34)

• A direct empirical proof of the existence of dark matter
• Observation of electron-antineutrino disappearance at Daya Bay
• Results from a search for dark matter in the complete LUX exposure
• Dark Matter Candidates from Particle Physics and Methods of Detection
• Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam
• Improved Naturalness with a Heavy Higgs: An Alternative Road to LHC Physics
• Dark Matter Results from First 98.7-day Data of PandaX-II Experiment
• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• micrOMEGAs4.1: two dark matter candidates
• Relic neutrino decoupling with flavour oscillations revisited
• Dark Matter Search Results from the Complete Exposure of the PICO-60 C${}_3$F${}_8$ Bubble Chamber
• Review of LHC Dark Matter Searches
• Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
• Basis-independent methods for the two-Higgs-doublet model III: The CP-conserving limit, custodial symmetry, and the oblique parameters S, T, U
• Thermal Dark Matter From A Highly Decoupled Sector
• How warm are non-thermal relics? Lyman-$\alpha$ bounds on out-of-equilibrium dark matter
• Cold keV dark matter from decays and scatterings
• Co-Decaying Dark Matter
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: The Most General Case
• Lyman-$\alpha$ constraints on freeze-in and superWIMPs
• Lower Mass Bounds on FIMP Dark Matter Produced via Freeze-In
• Freeze-in Production of Sterile Neutrino Dark Matter in U(1)${}_{\mathrm{B}-\mathrm{L}}$ Model
• Light Dirac neutrino portal dark matter with observable $\Delta N_{\mathrm{eff}}$
• Calculation of Momentum Distribution Function of a Non-thermal Fermionic Dark Matter
• Scalar Multiplet Dark Matter in a Fast Expanding Universe: resurrection of the desert region
• Primordial black holes and scotogenic dark matter
• Simple estimate of BBN sensitivity to light freeze-in dark matter
• The ScotoSinglet Model: A Scalar Singlet Extension of the Scotogenic Model
• Dark matter in a charged variant of the Scotogenic model
• An ultraviolet completion for the Scotogenic model
• Imprints of MeV Scale Hidden Dark Sector at Planck Data
• A generalization of the Scotogenic model
• Temperature effects on the $Z_2$ symmetry breaking in the scotogenic model

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• Study on the global minimum and $H\to \gamma \gamma$ in the Dirac scotogenic model
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• A Scotogenic Model as a Prototype for Leptogenesis with One Single Gauge Singlet
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