A Novel Approach to Study Atmospheric Neutrino Oscillation

TL;DR

This paper introduces a theoretical framework to analyze atmospheric neutrino oscillations, demonstrating its potential with PINGU data to resolve neutrino mass hierarchy and degeneracies within a year, while highlighting challenges in measuring the CP phase.

Contribution

It presents a new analytical framework for disentangling neutrino oscillation parameters, complementing existing tools like neutrino oscillograms, and applies it to PINGU to assess parameter resolution capabilities.

Findings

PINGU can resolve mass hierarchy within 1 year

Octant degeneracies can be resolved with this method

Measuring the CP phase remains challenging

Abstract

We develop a general theoretical framework to analytically disentangle the contributions of the neutrino mass hierarchy, the atmospheric mixing angle, and the CP phase, in neutrino oscillations. To illustrate the usefulness of this framework, especially that it can serve as a complementary tool to neutrino oscillogram in the study of atmospheric neutrino oscillations, we take PINGU as an example and compute muon- and electron-like event rates with event cuts on neutrino energy and zenith angle. Under the assumption of exact momentum measurements of neutrinos with a perfect e-$\mu$ identification and no backgrounds, we find that the PINGU experiment has the potential of resolving the neutrino mass hierarchy and the octant degeneracies within 1-year run, while the measurement of the CP phase is significantly more challenging. Our observation merits a serious study of the detector capability of estimating the neutrino momentum for both muon- and electron-like events.