Constraints on Lepton Number Violation with the 2 tonne$\cdot$yr CUORE Dataset

Abstract

Matter-antimatter asymmetry underlines the incompleteness of the current understanding of particle physics. Neutrinoless double-beta decay ($0\hat{I}½{\hat{I}}^2{\hat{I}}^2$) may help explain this asymmetry, while unveiling the Majorana nature of the neutrino. The CUORE experiment searches for $0\hat{I}½{\hat{I}}^2{\hat{I}}^2$ of ${}^{130}$Te using a tonne-scale cryogenic calorimeter operated at milli-kelvin temperatures. We report no evidence of $0\hat{I}½{\hat{I}}^2{\hat{I}}^2$ and place a lower limit on the half-life of $T_{1/2}>3.5\times$ 10${}^{25}$~years (90\% C.I.) with over 2~tonne$\cdot$year TeO${}_2$ exposure. The tools and techniques developed for this result and the 5 year stable operation of nearly 1000 detectors demonstrate crucial infrastructure for a future-generation experiment capable of searching for $0\hat{I}½{\hat{I}}^2{\hat{I}}^2$ across multiple isotopes.

This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on Oct 16, 2025, DOI:10.1126/science.adp6474