Xenon-Doped Liquid Argon TPCs as a Neutrinoless Double Beta Decay Platform

TL;DR

This paper proposes a 10 kton liquid argon TPC doped with xenon for neutrinoless double-beta decay searches, aiming to reach unprecedented sensitivity levels and extend the exploration of neutrino mass ordering.

Contribution

It introduces the concept of a large-scale xenon-doped liquid argon detector for neutrinoless double-beta decay, detailing design, background mitigation, and deployment considerations.

Findings

Potential to reach 2-4 meV sensitivity in $m_{\beta\beta}$

Xenon doping at 2% enhances detection capabilities

Background reduction is critical for achieving sensitivity goals

Abstract

Searches for neutrinoless double-beta decay continue to expand our understanding of the lepton sector, with experiments now pursuing ton-scale target masses with sensitivity to $m_{\beta\beta}$ covering the allowed parameter space for the inverted neutrino mass ordering. Continued searches for this rare decay will require scalable detector technologies to achieve significant increases in the target mass beyond the ton scale, in order to probe the normal ordering region. This work explores the concept of searching for neutrinoless double-beta decay in a 10 kton scale liquid argon time projection chamber (LArTPC) located deep underground and doped with percent-level quantities of xenon. We discuss the design requirements, background mitigation and detector R&D needs, and considerations for deployment in a modified DUNE far detector module. We find that such a detector could reach $m_{\beta\beta}$ sensitivity at the 2-4 meV range with xenon doping at 2% if significant background reductions can be achieved.