Sensitivity and discovery potential of the proposed nEXO experiment to neutrinoless double beta decay

TL;DR

The nEXO experiment aims to detect neutrinoless double beta decay in xenon-136 with unprecedented sensitivity, leveraging a large liquid-xenon detector and advanced measurement techniques to improve detection capabilities significantly.

Contribution

This paper introduces the nEXO detector concept, detailing its design and expected performance, achieving two orders of magnitude sensitivity improvement over current experiments.

Findings

Projected half-life sensitivity of ~10^28 years

Design features enable significant background reduction

Potential to advance understanding of neutrino properties

Abstract

The next-generation Enriched Xenon Observatory (nEXO) is a proposed experiment to search for neutrinoless double beta ($0\nu\beta\beta$) decay in $^{136}$Xe with a target half-life sensitivity of approximately $10^{28}$ years using $5\times10^3$ kg of isotopically enriched liquid-xenon in a time projection chamber. This improvement of two orders of magnitude in sensitivity over current limits is obtained by a significant increase of the $^{136}$Xe mass, the monolithic and homogeneous configuration of the active medium, and the multi-parameter measurements of the interactions enabled by the time projection chamber. The detector concept and anticipated performance are presented based upon demonstrated realizable background rates.