Probing Pseudo-Dirac Neutrinos with Astrophysical Sources at IceCube

TL;DR

This paper proposes a novel astrophysical method using IceCube observations to detect pseudo-Dirac neutrinos with extremely small mass-squared differences, surpassing terrestrial experiment sensitivities.

Contribution

It introduces a new approach to probe neutrino mass nature using astrophysical sources, significantly extending the sensitivity to tiny mass-squared differences.

Findings

Method can detect $ ext{delta} m^2$ down to $10^{-21}~ ext{eV}^2$

Improves terrestrial experiment reach by over a billion times

Multiple sources can enhance sensitivity and coverage

Abstract

The recent observation of NGC 1068 by the IceCube Neutrino Observatory has opened a new window to neutrino physics with astrophysical baselines. In this Letter, we propose a new method to probe the nature of neutrino masses using these observations. In particular, our method enables searching for signatures of pseudo-Dirac neutrinos with mass-squared differences that reach down to $\delta m^2 \gtrsim 10^{-21}~\text{eV}^2$, improving the reach of terrestrial experiments by more than a billion. Finally, we discuss how the discovery of a constellation of neutrino sources can further increase the sensitivity and cover a wider range of $\delta m^2$ values.