Searching for sterile neutrinos in ice

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 $|U_{μ0}|^2 \sim (0.02 - 0.04)$. 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 $ν_μ-$events have been computed for the simplest $ν_s-$mass, and $ν_s - ν_μ$ mixing schemes and confronted with the IceCube data. An illustrative statistical analysis of the present data shows that in the $ν_s-$mass mixing case the sterile neutrinos with parameters required by LSND/MiniBooNE can be excluded at about $3σ$ level. The $ν_s- ν_μ$ mixing scheme, however, can not be ruled out with currently available IceCube data.

41 pages, 16 figures. Accepted for publication in JHEP. Minor changes from the previous version