Cornering (quasi) degenerate neutrinos with cosmology

Abstract

In light of the improved sensitivities of cosmological observations, we examine the status of quasi-degenerate neutrino mass scenarios. Within the simplest extension of the standard cosmological model with massive neutrinos, we find that quasi-degenerate neutrinos are severely constrained by present cosmological data and neutrino oscillation experiments. % % We find that Planck 2018 observations of cosmic microwave background (CMB) anisotropies disfavour quasi-degenerate neutrino masses at $2.4$ Gaussian $\sigma$'s, while adding Baryon acoustic oscillations (BAO) data brings the rejection to 5.9$\sigma$'s. % The highest statistical significance with which one would be able to rule out quasi-degeneracy would arise if the sum of neutrino masses is $\Sigma m_{\nu }=60$ \meV (the minimum allowed by neutrino oscillation experiments); % indeed a sensitivity of 15 meV, as expected from a combination of future cosmological probes, would further improve the rejection level up to 17$\sigma$. % We discuss the robustness of these projections with respect to assumptions on the underlying cosmological model, and also compare them with bounds from $\beta$ decay endpoint and neutrinoless double beta decay studies.

arXiv comment19 pages, 6 figures, 1 table

References in corpus (20)

• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• The 6dF Galaxy Survey: Baryon Acoustic Oscillations and the Local Hubble Constant
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• Cosmology and Fundamental Physics with the Euclid Satellite
• Global analysis of three-flavour neutrino oscillations: synergies and tensions in the determination of theta_23, delta_CP, and the mass ordering
• Underlying A_4 Symmetry for the Neutrino Mass Matrix and the Quark Mixing Matrix
• Status of neutrino oscillations 2018: first hint for normal mass ordering and improved CP sensitivity
• Unveiling $\nu$ secrets with cosmological data: neutrino masses and mass hierarchy
• Background free search for neutrinoless double beta decay with GERDA Phase II
• Constraints on the sum of the neutrino masses in dynamical dark energy models with $w(z)\ge -1$ are tighter than those obtained in $\Lambda$CDM
• The LiteBIRD Satellite Mission - Sub-Kelvin Instrument
• Cosmological constraints in extended parameter space from the Planck 2018 Legacy release
• The promising future of a robust cosmological neutrino mass measurement
• SO(10) grand unification model for degenerate neutrino masses
• Quark-Lepton Mass Relation and CKM mixing in an A4 Extension of the Minimal Supersymmetric Standard Model
• Neutrino Unification
• From Hierarchical to Partially Degenerate Neutrinos via Type II Upgrade of Type I See-Saw Models
• Naturally Degenerate Neutrinos
• Splitting of Three Nearly Mass-Degenerate Neutrinos
• Cosmology-marginalized approaches in Bayesian model comparison: the neutrino mass as a case study

Cited by in corpus (5)

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• Status and Perspectives of Neutrino Physics