Searching for sterile neutrinos in ice

TL;DR

This paper investigates the potential to detect sterile neutrinos with ~1 eV mass using IceCube atmospheric neutrino data, analyzing oscillation effects and comparing predictions with observations to constrain sterile neutrino models.

Contribution

It provides a detailed analytical and numerical study of sterile neutrino oscillations in IceCube data, testing specific mixing schemes against experimental results.

Findings

Sterile neutrinos with LSND/MiniBooNE parameters are excluded in the mass mixing scheme at 3σ.

The $ u_s- u_bc$ mixing scheme remains compatible with current IceCube data.

Oscillation probabilities are characterized for various sterile neutrino mixing scenarios.

Abstract

Oscillation interpretation of the results from the LSND, MiniBooNE and some other experiments requires existence of sterile neutrino with mass $\sim 1$ eV and mixing with the active neutrinos $|U_{\mu 0}|^2 \sim (0.02 - 0.04)$. It has been realized some time ago that existence of such a neutrino affects significantly the fluxes of atmospheric neutrinos in the TeV range which can be tested by the IceCube Neutrino Observatory. In view of the first IceCube data release we have revisited the oscillations of high energy atmospheric neutrinos in the presence of one sterile neutrino. Properties of the oscillation probabilities are studied in details for various mixing schemes both analytically and numerically. The energy spectra and angular distributions of the $\nu_\mu-$events have been computed for the simplest $\nu_s-$mass, and $\nu_s - \nu_\mu$ mixing schemes and confronted with the IceCube data. An illustrative statistical analysis of the present data shows that in the $\nu_s-$mass mixing case the sterile neutrinos with parameters required by LSND/MiniBooNE can be excluded at about $3\sigma$ level. The $\nu_s- \nu_\mu$ mixing scheme, however, can not be ruled out with currently available IceCube data.