Measurement of Atmospheric Neutrino Oscillations at 6-56 GeV with IceCube DeepCore

TL;DR

This paper reports a measurement of atmospheric neutrino oscillation parameters using three years of IceCube DeepCore data, covering energies from 5.6 to 56 GeV, and finds results consistent with other experiments.

Contribution

First measurement of atmospheric neutrino oscillations at energies as low as 5 GeV using IceCube DeepCore, extending the energy range of oscillation studies.

Findings

Measured m^2_{32} = 2.31^{+0.11}_{-0.13} imes 10^{-3} eV^2

Measured sin^2 heta_{23} = 0.51^{+0.07}_{-0.09}

Results are consistent with accelerator and reactor experiments.

Abstract

We present a measurement of the atmospheric neutrino oscillation parameters using three years of data from the IceCube Neutrino Observatory. The DeepCore infill array in the center of IceCube enables detection and reconstruction of neutrinos produced by the interaction of cosmic rays in the Earth's atmosphere at energies as low as $\sim5$ GeV. That energy threshold permits measurements of muon neutrino disappearance, over a range of baselines up to the diameter of the Earth, probing the same range of $L/E_\nu$ as long-baseline experiments but with substantially higher energy neutrinos. This analysis uses neutrinos from the full sky with reconstructed energies from $5.6$ - $56$ GeV. We measure $\Delta m^2_{32}=2.31^{+0.11}_{-0.13} \times 10^{-3}$ eV$^2$ and $\sin^2 \theta_{23}=0.51^{+0.07}_{-0.09}$, assuming normal neutrino mass ordering. These results are consistent with, and of similar precision to, those from accelerator and reactor-based experiments.