10942 10.1140/epjc/s10052-022-10942-5 1033 57 Final results on the 0 ν β β decay half-life limit of 100 Mo from the CUPID-Mo experiment Regular Article - Experimental Physics 1 20 2022 10 24 2022 2 17 2022 10 23 2022 11 15 Nuclear Physics Contract Nos. DE-AC02-05CH11231 Contract Nos. DE-FG02-08ER41551 Contract Nos. DE-SC0011091 H2020 Marie Sklodowska-Curie Actions Grant Agreement No. 754496 Agence Nationale de la Recherche ANR-11-IDEX- 0003-01 – Project BSM-nu LUMINEU project National Research Foundation of Ukraine Grant No. 2020.02/0011 National Academy of Sciences of Ukraine program “Laboratory of young scientists” Office for Science and Technology of the Embassy of France in the United States France-Berkeley MISTI-France Chateaubriand Fell. Russian Science Foundation grant No. 18-12-00003 The Author(s) 2022 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development. 10052 82 82 11 11 C. Augier A. S. Barabash F. Bellini G. Benato M. Beretta L. Bergé J. Billard Yu. A. Borovlev L. Cardani N. Casali A. Cazes M. Chapellier D. Chiesa I. Dafinei F. A. Danevich M. De Jesus P. de Marcillac T. Dixon L. Dumoulin K. Eitel F. Ferri B. K. Fujikawa J. Gascon L. Gironi A. Giuliani andrea.giuliani@ijclab.in2p3.fr V. D. Grigorieva M. Gros D. L. Helis H. Z. Huang R. Huang L. Imbert J. Johnston A. Juillard H. Khalife M. Kleifges V. V. Kobychev Yu. G. Kolomensky S. I. Konovalov P. Loaiza L. Ma E. P. Makarov R. Mariam L. Marini S. Marnieros X.-F. Navick C. Nones E. B. Norman E. Olivieri J. L. Ouellet L. Pagnanini L. Pattavina B. Paul M. Pavan H. Peng G. Pessina S. Pirro D. V. Poda O. G. Polischuk S. Pozzi E. Previtali Th. Redon A. Rojas S. Rozov V. Sanglard J. A. Scarpaci B. Schmidt Y. Shen V. N. Shlegel V. Singh C. Tomei V. I. Tretyak V. I. Umatov L. Vagneron M. Velázquez B. Welliver L. Winslow M. Xue E. Yakushev M. Zarytskyy A. S. Zolotarova grid.7849.2 0000 0001 2150 7757 Univ Lyon, Université Lyon 1, CNRS/IN2P3, IP2I-Lyon 69622 Villeurbanne France grid.18919.38 0000000406204151 National Research Centre Kurchatov Institute, Institute of Theoretical and Experimental Physics 117218 Moscow Russia grid.7841.a Dipartimento di Fisica Sapienza Università di Roma P.le Aldo Moro 2 00185 Rome Italy grid.470218.8 INFN, Sezione di Roma P.le Aldo Moro 2 00185 Rome Italy grid.457342.3 0000 0004 0619 0319 IRFU, CEA, Université Paris-Saclay 91191 Gif-sur-Yvette France grid.466877.c 0000 0001 2201 8832 INFN, Laboratori Nazionali del Gran Sasso 67100 Assergi AQ Italy grid.47840.3f 0000 0001 2181 7878 Department of Physics University of California Berkeley CA 94720 USA grid.508754.b Université Paris-Saclay, CNRS/IN2P3, IJCLab 91405 Orsay France grid.425759.8 0000 0004 0638 042X Nikolaev Institute of Inorganic Chemistry 630090 Novosibirsk Russia grid.7563.7 0000 0001 2174 1754 Dipartimento di Fisica Università di Milano-Bicocca 20126 Milan Italy grid.470207.6 0000 0004 8390 4143 INFN, Sezione di Milano-Bicocca 20126 Milan Italy grid.450331.0 Institute for Nuclear Research Kyiv 03028 Ukraine grid.7892.4 0000 0001 0075 5874 Institute for Astroparticle Physics Karlsruhe Institute of Technology 76021 Karlsruhe Germany grid.184769.5 0000 0001 2231 4551 Nuclear Science Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA grid.466750.6 0000 0004 6005 2566 Gran Sasso Science Institute 67100 L’Aquila Italy grid.8547.e 0000 0001 0125 2443 Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) Fudan University Shanghai 200433 People’s Republic of China grid.116068.8 0000 0001 2341 2786 Massachusetts Institute of Technology Cambridge MA 02139 USA grid.7892.4 0000 0001 0075 5874 Institute for Data Processing and Electronics Karlsruhe Institute of Technology 76021 Karlsruhe Germany grid.47840.3f 0000 0001 2181 7878 Department of Nuclear Engineering University of California Berkeley CA 94720 USA grid.6936.a 0000000123222966 Physik Department Technische Universität München 85748 Garching Germany grid.59053.3a 0000000121679639 Department of Modern Physics University of Science and Technology of China Hefei 230027 People’s Republic of China LSM, Laboratoire Souterrain de Modane 73500 Modane France grid.33762.33 0000000406204119 Laboratory of Nuclear Problems, JINR 141980 Dubna Moscow Region Russia grid.16753.36 0000 0001 2299 3507 Department of Physics and Astronomy Northwestern University Evanston IL 60208 USA grid.462639.c 0000 0001 2170 1576 Université Grenoble Alpes, CNRS, Grenoble INP, SIMAP 38402 Saint Martin d’Héres France Abstract The CUPID-Mo experiment to search for 0 ν β β decay in 100 Mo has been recently completed after about 1.5 years of operation at Laboratoire Souterrain de Modane (France). It served as a demonstrator for CUPID, a next generation 0 ν β β decay experiment. CUPID-Mo was comprised of 20 enriched Li 2 100 MoO 4 scintillating calorimeters, each with a mass of ∼ 0.2  kg, operated at ∼ 20  mK. We present here the final analysis with the full exposure of CUPID-Mo ( 100 Mo exposure of 1.47 kg × year ) used to search for lepton number violation via 0 ν β β decay. We report on various analysis improvements since the previous result on a subset of data, reprocessing all data with these new techniques. We observe zero events in the region of interest and set a new limit on the 100 Mo 0 ν β β decay half-life of T 1 / 2 0 ν {1.8}\times 10^{24}$$]]> > 1.8 × 10 24  year (stat. + syst.) at 90% CI. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of $$]]> m β β   < ( 0.28 - 0.49 )  eV, dependent upon the nuclear matrix element utilized.