Prediction of Energy Resolution in the JUNO Experiment

TL;DR

This study evaluates the energy resolution of the JUNO neutrino experiment, achieving a 2.95% resolution at 1 MeV through comprehensive simulation, which is crucial for neutrino mass ordering determination.

Contribution

It provides a detailed simulation-based assessment of JUNO's energy resolution, incorporating detector effects and guiding future measurements and detector design improvements.

Findings

Energy resolution of 2.95% at 1 MeV achieved

Major effects on energy resolution quantified

Simulation approach effectively models detector performance

Abstract

This paper presents an energy resolution study of the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3\% at 1~MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of the liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The results of study reveal an energy resolution of 2.95\% at 1~MeV. Furthermore, this study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection. Moreover, it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.