# Presupernova neutrino signals as potential probes of neutrino mass hierarchy

## TL;DR

This paper explores how presupernova neutrino signals detected at JUNO could determine the neutrino mass hierarchy, emphasizing the importance of precise predictions, proximity of the star, and background reduction.

## Contribution

It proposes a method to determine the neutrino mass hierarchy using presupernova neutrino signals, including a model-independent approach with both neutrino types.

## Key findings

- Detection within 440-880 pc can determine hierarchy at >95% confidence
- Betelgeuse signals could reveal hierarchy if uncertainties are reduced
- Background reduction is crucial for the feasibility of the method

## Abstract

We assess the potential of using presupernova neutrino signals at the Jiangmen Underground Neutrino Observatory (JUNO) to probe the yet-unknown neutrino mass hierarchy. Using models for stars of 12, 15, 20, and 25 solar masses, we find that if the electron antineutrino signals from such a star can be predicted precisely and the star is within ~440-880 pc, the number of events of electron antineutrino captures on protons detected within one day of its explosion allows to determine the hierarchy at the > ~95% confidence level. For determination at this level using such signals from Betelgeuse, which is at a distance of ~222 pc, the uncertainty in the predicted number of signals needs to be < ~14-30%. In view of more realistic uncertainties, we discuss and advocate a model-independent determination using both electron neutrino and antineutrino signals from Betelgeuse. This method is feasible if the cosmogenic background for neutrino-electron scattering events can be reduced by a factor of ~2.5-10 from the current estimate. Such reduction might be achieved by using coincidence of the background events, the exploration of which for JUNO is highly desirable.