The benefits of a near detector for JUNO

TL;DR

This paper emphasizes the importance of a near detector for JUNO to accurately measure reactor antineutrino spectra, which is crucial for determining neutrino mass hierarchy using oscillation frequency beat patterns.

Contribution

It highlights the necessity of an experimental reference spectrum with similar energy resolution to JUNO to account for reactor flux micro-structure effects.

Findings

Micro-structure in reactor antineutrino fluxes affects measurements.

A near detector can provide essential reference data.

Accurate spectrum measurement is vital for neutrino mass hierarchy determination.

Abstract

It has been proposed to determine the mass hierarchy of neutrinos by exploiting the beat between the oscillation frequencies corresponding to the two neutrino mass squared differences. JUNO is based on this concept and uses a large liquid scintillator detector at a distance of 53km from a powerful nuclear reactor complex. We argue that the micro-structure present in antineutrino fluxes from nuclear reactors makes it essential to experimentally determine a reference spectrum with an energy resolution very similar to the one of JUNO.