Expected performance of an ideal liquid argon neutrino detector with enhanced sensitivity to scintillation light

TL;DR

This paper explores the potential of large liquid argon neutrino detectors with enhanced scintillation light sensitivity to improve energy resolution and neutrino/antineutrino separation, based on detailed simulations.

Contribution

It demonstrates that high light collection efficiency in large LAr detectors can significantly enhance neutrino energy reconstruction and flavor identification capabilities.

Findings

Achieves 3.3% energy resolution at 4 GeV for electron neutrinos.

Attains about 50% muon neutrino identification efficiency.

Maintains muon antineutrino misidentification rates at a few percent.

Abstract

Scintillation light is used in liquid argon (LAr) neutrino detectors to provide a trigger signal, veto information against cosmic rays, and absolute event timing. In this work, we discuss additional opportunities offered by detectors with enhanced sensitivity to scintillation light, that is with light collection efficiencies of about $10^{-3}$. We focus on two key detector performance indicators for neutrino oscillation physics: calorimetric neutrino energy reconstruction and neutrino/antineutrino separation in a non-magnetized detector. Our results are based on detailed simulations, with neutrino interactions modelled according to the GENIE event generator, while the charge and light responses of a large LAr ideal detector are described by the Geant4 and NEST simulation tools. A neutrino energy resolution as good as 3.3\% RMS for 4 GeV electron neutrino charged-current interactions can in principle be obtained in a large detector of this type, by using both charge and light information. By exploiting muon capture in argon and scintillation light information to veto muon decay electrons, we also obtain muon neutrino identification efficiencies of about 50\%, and muon antineutrino misidentification rates at the few percent level, for few-GeV neutrino interactions that are fully contained. We argue that the construction of large LAr detectors with sufficiently high light collection efficiencies is in principle possible.