Eur. Phys. J. C (2021) 81: 567
https://doi.org/10.1140/epjc/s10052-021-09317-z

Regular Article - Experimental Physics

Search for double-beta decay of to the states of with CUORE

¹ Department of Physics and Astronomy, University of South Carolina, 29208, Columbia, SC, USA
² Department of Physics and Astronomy, University of California, 90095, Los Angeles, CA, USA
³ INFN–Laboratori Nazionali di Legnaro, 35020, Legnaro, Padua, Italy
⁴ INFN–Sezione di Bologna, 40127, Bologna, Italy
⁵ Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome, Italy
⁶ INFN–Sezione di Roma, 00185, Rome, Italy
⁷ INFN–Laboratori Nazionali del Gran Sasso, 67100, Assergi, L’Aquila, Italy
⁸ INFN–Sezione di Milano-Bicocca, 20126, Milan, Italy
⁹ Dipartimento di Fisica, Università di Milano-Bicocca, 20126, Milan, Italy
¹⁰ Center for Neutrino Physics, Virginia Polytechnic Institute and State University, 24061, Blacksburg, VA, USA
¹¹ INFN–Sezione di Genova, 16146, Genoa, Italy
¹² Dipartimento di Fisica, Università di Genova, 16146, Genoa, Italy
¹³ Massachusetts Institute of Technology, 02139, Cambridge, MA, USA
¹⁴ Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University, 200433, Shanghai, China
¹⁵ Department of Physics, University of California, 94720, Berkeley, CA, USA
¹⁶ Nuclear Science Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
¹⁷ INFN–Gran Sasso Science Institute, 67100, L’Aquila, Italy
¹⁸ Wright Laboratory, Department of Physics, Yale University, 06520, New Haven, CT, USA
¹⁹ INFN–Laboratori Nazionali di Frascati, 00044, Frascati, Rome, Italy
²⁰ Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405, Orsay, France
²¹ Physics Department, California Polytechnic State University, 93407, San Luis Obispo, CA, USA
²² INPAC and School of Physics and Astronomy, Shanghai Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University, 200240, Shanghai, China
²³ Dipartimento di Fisica e Astronomia, Alma Mater Studiorum–Università di Bologna, 40127, Bologna, Italy
²⁴ Service de Physique des Particules, CEA/Saclay, 91191, Gif-sur-Yvette, France
²⁵ Lawrence Livermore National Laboratory, 94550, Livermore, CA, USA
²⁶ Department of Nuclear Engineering, University of California, 94720, Berkeley, CA, USA
²⁷ Dipartimento di Ingegneria Civile e Meccanica, Università degli Studi di Cassino e del Lazio Meridionale, 03043, Cassino, Italy
²⁸ Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, 21211, Baltimore, MD, USA
²⁹ INFN–Sezione di Padova, 35131, Padua, Italy
³⁰ Engineering Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA

ⁿ cuore-spokesperson@lngs.infn.it

Received: 27 January 2021
Accepted: 7 June 2021
Published online: 1 July 2021

Abstract

The CUORE experiment is a large bolometric array searching for the lepton number violating neutrino-less double beta decay () in the isotope . In this work we present the latest results on two searches for the double beta decay (DBD) of to the first excited state of : the decay and the Standard Model-allowed two-neutrinos double beta decay (). Both searches are based on a 372.5 kgyr TeO 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 for the decay and for the decay. No significant evidence for either of the decay modes was observed and a Bayesian lower bound at C.I. on the decay half lives is obtained as: for the mode and for the mode. These represent the most stringent limits on the DBD of Te to excited states and improve by a factor the previous results on this process.