Searches for Sterile Neutrinos with the IceCube Detector

TL;DR

This study used the IceCube detector to search for sterile neutrinos by analyzing atmospheric muon neutrino data, setting new limits on their possible mixing parameters and excluding certain regions suggested by previous experiments.

Contribution

The paper presents the first IceCube-based search for sterile neutrinos in the 320 GeV to 20 TeV range, providing new exclusion limits on the 3+1 model parameters.

Findings

No evidence of sterile neutrino oscillations was observed.

New exclusion limits on mixing angles and mass-squared differences were established.

The global best fit region from appearance experiments is largely excluded.

Abstract

The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy in the approximate 320 GeV to 20 TeV range, to search for the oscillation signatures of light sterile neutrinos. No evidence for anomalous $\nu_\mu$ or $\bar{\nu}_\mu$ disappearance is observed in either of two independently developed analyses, each using one year of atmospheric neutrino data. New exclusion limits are placed on the parameter space of the 3+1 model, in which muon antineutrinos would experience a strong MSW-resonant oscillation. The exclusion limits extend to $\mathrm{sin}^2 2\theta_{24} \leq$ 0.02 at $\Delta m^2 \sim$ 0.3 $\mathrm{eV}^2$ at the 90\% confidence level. The allowed region from global analysis of appearance experiments, including LSND and MiniBooNE, is excluded at approximately the 99\% confidence level for the global best fit value of $|$U$_{e4}|^2$.