Searching for $0\nu\beta\beta$ decay in $^{136}$Xe -- towards the tonne-scale and beyond

TL;DR

This paper reviews the current and future efforts in searching for neutrinoless double-beta decay in $^{136}$Xe, highlighting experimental progress, scaling strategies, and new detection techniques to probe fundamental physics.

Contribution

It discusses the status of KamLAND-Zen and EXO-200 experiments, their planned upgrades, and introduces two new developments for identifying decay events.

Findings

Next-generation experiments aim to explore the inverted hierarchy parameter space.

Both techniques are scalable to larger volumes with new detection methods.

Current experiments set the most stringent limits on $0 uetaeta$ decay in $^{136}$Xe.

Abstract

The quest for neutrinoless double-beta decay ($0\nu\beta\beta$) is a promising experimental approach to search for lepton number violation in weak interactions, a key ingredient in generating the matter-antimatter asymmetry through models of Leptogenesis. The $^{136}$Xe-based $0\nu\beta\beta$ experiments KamLAND-Zen and EXO-200 currently set the most stringent limits on this process using two very different techniques. Each are preparing the next generation experiment, which will search for $0\nu\beta\beta$ in the parameter space corresponding to the inverted hierarchy for neutrino mass. Both of these techniques scale well to larger volumes while incorporating interesting new techniques. We present the status of current and next generation experiments of these collaborations and present two developments with the potential to identify $\beta\beta$ decay events.