Experimental Conditions for Determination of the Neutrino Mass Hierarchy with Reactor Antineutrinos

TL;DR

This paper identifies optimal experimental conditions, including detector resolution and baseline distance, necessary to determine the neutrino mass hierarchy with over 90% probability using reactor antineutrinos.

Contribution

It provides specific requirements on energy resolution and baseline distance to reliably determine the neutrino mass hierarchy with high confidence.

Findings

Energy resolution must be better than 0.04/√E_ν for effective hierarchy determination.

Optimal baseline distance is around 48-53 km from the reactor.

Achieving >90% probability requires precise energy measurement and suitable detector placement.

Abstract

This article reports the optimized experimental requirements to determine neutrino mass hierarchy using electron antineutrinos ($\bar{\nu}_e$) generated in a nuclear reactor. The features of the neutrino mass hierarchy can be extracted from the $|\Delta m^{2}_{31}|$ and $|\Delta m^{2}_{32}|$ oscillations by applying the Fourier sine and cosine transform to the $L/E$ spectrum. To determine the neutrino mass hierarchy above 90\% probability, the requirements on the energy resolution as a function of the baseline are studied at $\sin 2\theta_{13}=0.1$. If the energy resolution of the neutrino detector is less than $0.04/ \sqrt{E_{\nu}}$ and the determination probability obtained from Bayes' theorem is above 90\%, the detector needs to be located around 48--53 km from the reactor(s) to measure the energy spectrum of $\bar{\nu}_e$. These results will be helpful for setting up an experiment to determine the neutrino mass hierarchy, which is an important problem in neutrino physics.