PINGU Sensitivity to the Neutrino Mass Hierarchy

TL;DR

PINGU aims to determine the neutrino mass hierarchy with high statistical significance using a specialized detector in Antarctica, showing promising sensitivity and robustness against uncertainties.

Contribution

This study demonstrates the feasibility and projected sensitivity of PINGU to measure the neutrino mass hierarchy, including detector design and uncertainty analysis.

Findings

Sensitivity of 2.1 to 3.4 sigma per year depending on design

Limited impact of systematic and theoretical uncertainties

Potential 3 sigma measurement by 2020

Abstract

The neutrino mass hierarchy is one of the few remaining unknown parameters in the neutrino sector and hence a primary focus of the experimental community. The Precision IceCube Next Generation Upgrade (PINGU) experiment, to be co-located with the IceCube DeepCore detector in the deep Antarctic glacier, is being designed to provide a first definitive measurement of the mass hierarchy. We have conducted feasibility studies for the detector design that demonstrate a statistically-limited sensitivity to the hierarchy of 2.1 sigma to 3.4 sigma per year is possible, depending on the detector geometry (20 to 40 strings) and analysis efficiencies. First studies of the effects of systematic and theoretical uncertainties show limited impact on the overall sensitivity to the hierarchy. Assuming deployment of the first array elements in the 2016/17 austral summer season a 3 sigma measurement of the hierarchy is anticipated with PINGU in 2020.