A Combined View of Sterile-Neutrino Constraints from CMB and Neutrino Oscillation Measurements

TL;DR

This paper compares constraints on sterile neutrinos from CMB data and neutrino oscillation experiments, translating Planck constraints into the oscillation parameter space to evaluate their relative sensitivities.

Contribution

It is the first to express Planck constraints on sterile neutrinos in the same parameter space as oscillation experiments, enabling direct comparison.

Findings

Planck and muon-neutrino disappearance experiments have similar sensitivity.

The translation of CMB constraints into oscillation parameters is achieved.

The analysis covers current and future neutrino experiments.

Abstract

We perform a comparative analysis of constraints on sterile neutrinos from the Planck experiment and from current and future neutrino oscillation experiments (MINOS, IceCube, SBN). For the first time, we express the Planck constraints on $N_{\rm eff}$ and $m_{\rm eff}^{\rm sterile}$ from the Cosmic Microwave Background in the parameter space used by oscillation experiments using both mass-squared differences and mixing angles. In a model with a single sterile neutrino species and using standard assumptions, we find that the Planck data and the oscillation experiments measuring muon-neutrino disappearance have similar sensitivity.