Reactor neutrino liquid xenon coherent elastic scattering experiment

TL;DR

RELICS is a proposed liquid xenon detector experiment designed to observe coherent elastic neutrino-nucleus scattering from reactor antineutrinos, aiming to explore neutrino properties and BSM physics with optimized detection strategies.

Contribution

This work presents the design, optimization, and sensitivity analysis of the RELICS experiment using LXeTPC technology for CEvNS detection at reactors, including background suppression and physics potential.

Findings

Expected 4639.7 CEvNS events in 32 kg*yr exposure

Background events estimated at 1687.8

Potential to improve constraints on non-standard neutrino interactions

Abstract

Coherent elastic neutrino-nucleus scattering (CEvNS) provides a unique probe for neutrino properties Beyond the Standard Model (BSM) physics. REactor neutrino LIquid xenon Coherent Scattering experiment (RELICS), a proposed reactor neutrino program using liquid xenon time projection chamber (LXeTPC) technology, aims to investigate the CEvNS process of antineutrinos off xenon atomic nuclei. In this work, the design of the experiment is studied and optimized based on Monte Carlo (MC) simulations. To achieve a sufficiently low energy threshold for CEvNS detection, an ionization-only analysis channel is adopted for RELICS. A high emission rate of delayed electrons after a big ionization signal is the major background, leading to an analysis threshold of 120 photo-electrons in the CEvNS search. The second largest background, nuclear recoils induced by cosmic-ray neutrons, is suppressed via a passive water shield. The physics potential of RELICS is explored with a 32 kg*yr exposure at a baseline of 25 m from a reactor core with a 3 GW thermal power. In an energy range of 120 to 300 PE, corresponding to an average nuclear recoil from 0.63 to 1.36 keV considering the liquid xenon response and detector-related effect, we expect 4639.7 CEvNS and 1687.8 background events. The sensitivity of RELICS to the weak mixing angle is investigated at a low momentum transfer. Our study shows that RELICS can further improve the constraints on the non-standard neutrino interaction (NSI) compared to the current best results.