Search for double-beta decay of [Formula omitted] to the [Formula omitted] states of [Formula omitted] with CUORE

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2021-07, Vol.81 (7)
• Main Authors: Adams, D. Q, Alduino, C, Alfonso, K, Avignone, F. T. III, Azzolini, O, Bari, G, Bellini, F
• Format: Article
• Language: English
• Subjects: Gamma rays
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-021-09317-z

The CUORE experiment is a large bolometric array searching for the lepton number violating neutrino-less double beta decay ( [Formula omitted]) in the isotope [Formula omitted]. In this work we present the latest results on two searches for the double beta decay (DBD) of [Formula omitted] to the first [Formula omitted] excited state of [Formula omitted]: the [Formula omitted] decay and the Standard Model-allowed two-neutrinos double beta decay ( [Formula omitted]). Both searches are based on a 372.5 kg [Formula omitted]yr TeO [Formula omitted] exposure. The de-excitation gamma rays emitted by the excited Xe nucleus in the final state yield a unique signature, which can be searched for with low background by studying coincident events in two or more bolometers. The closely packed arrangement of the CUORE crystals constitutes a significant advantage in this regard. The median limit setting sensitivities at 90% Credible Interval (C.I.) of the given searches were estimated as [Formula omitted] for the [Formula omitted] decay and [Formula omitted] for the [Formula omitted] decay. No significant evidence for either of the decay modes was observed and a Bayesian lower bound at [Formula omitted] C.I. on the decay half lives is obtained as: [Formula omitted] for the [Formula omitted] mode and [Formula omitted] for the [Formula omitted] mode. These represent the most stringent limits on the DBD of [Formula omitted]Te to excited states and improve by a factor [Formula omitted] the previous results on this process.