Searches for sterile neutrinos with IceCube DeepCore

TL;DR

This paper demonstrates that the IceCube DeepCore detector can significantly constrain sterile neutrino mixing parameters in the 10-100 GeV energy range, potentially identifying neutrino mass hierarchy and excluding certain sterile neutrino models.

Contribution

It provides detailed calculations of neutrino oscillation probabilities and event distributions, showing how DeepCore data can test sterile neutrino hypotheses and improve existing constraints.

Findings

DeepCore can exclude sterile neutrino mixing |U_{μ4}|^2 ≥ 0.02

Neutrino mass hierarchy can be identified if sterile neutrinos exist

Combining DeepCore and high-energy IceCube data enhances sensitivity to sterile neutrinos

Abstract

We show that study of the atmospheric neutrinos in the 10--100 GeV energy range by DeepCore sub-array of the IceCube Neutrino Observatory can substantially constrain the mixing of sterile neutrinos of mass $\sim 1$ eV with active neutrinos. In the scheme with one sterile neutrino we calculate $\nu_\mu-$ and $\bar{\nu}_\mu-$ oscillation probabilities as well as zenith angle distributions of $\nu_\mu^{CC}$ events in different energy intervals in DeepCore. The distributions depend on the mass hierarchy of active neutrinos. Therefore, in principle, the hierarchy can be identified, if $\nu_s$ exists. After a few years of exposure the DeepCore data will allow to exclude the mixing $|U_{\mu 4}|^2 \geq 0.02$ indicated by the LSND/MiniBooNE results. Combination of the DeepCore and high energy IceCube data will further improve sensitivity to $\nu_s$ mixing parameters.