https://doi.org/10.1140/epjc/s10052-023-11830-2
Regular Article - Experimental Physics
The background model of the CUPID-Mo 
experiment
1
Université Lyon 1, CNRS/IN2P3, IP2I-Lyon, 69622, Villeurbanne, France
2
National Research Centre Kurchatov Institute, Kurchatov Complex of Theoretical and Experimental Physics, 117218, Moscow, Russia
3
Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185, Rome, Italy
4
INFN, Sezione di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133, Rome, Italy
5
Gran Sasso Science Institute, 67100, L’Aquila, Italy
6
INFN, Laboratori Nazionali del Gran Sasso, 67100, Assergi, AQ, Italy
7
Department of Physics, University of California, 94720, Berkeley, CA, USA
8
Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405, Orsay, France
9
Nikolaev Institute of Inorganic Chemistry, 630090, Novosibirsk, Russia
10
Dipartimento di Fisica, Università di Milano-Bicocca, 20126, Milan, Italy
11
INFN, Sezione di Milano-Bicocca, 20126, Milan, Italy
12
Institute for Nuclear Research of NASU, 03028, Kyiv, Ukraine
13
Institute for Astroparticle Physics, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
14
Nuclear Science Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
15
IRFU, CEA, Université Paris-Saclay, 91191, Gif-sur-Yvette, France
16
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, 200433, Shanghai, People’s Republic of China
17
Massachusetts Institute of Technology, 02139, Cambridge, MA, USA
18
Institute for Data Processing and Electronics, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
19
Department of Physics, University of Jyväskylä, PO Box 35, 40014, Jyvaskyla, Finland
20
Finnish Institute for Educational Research, University of Jyväskylä, P.O. Box 35, 40014, Jyvaskyla, Finland
21
Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, 06520-8120, New Haven, CT, USA
22
Department of Nuclear Engineering, University of California, 94720, Berkeley, CA, USA
23
Physik Department, Technische Universität München, 85748, Garching, Germany
24
Department of Modern Physics, University of Science and Technology of China, 230027, Hefei, People’s Republic of China
25
LSM, Laboratoire Souterrain de Modane, 73500, Modane, France
26
Laboratory of Nuclear Problems, JINR, 141980, Dubna, Moscow Region, Russia
27
Université Grenoble Alpes, CNRS, Grenoble INP, SIMAP, 38402, Saint Martin d’Héres, France
aj
leonard.imbert@ijclab.in2p3.fr
Received:
2
May
2023
Accepted:
10
July
2023
Published online:
28
July
2023
CUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation decay experiment, CUPID. It consisted of an array of 20 enriched Li
MoO
bolometers and 20 Ge light detectors and has demonstrated that the technology of scintillating bolometers with particle identification capabilities is mature. Furthermore, CUPID-Mo can inform and validate the background prediction for CUPID. In this paper, we present a detailed model of the CUPID-Mo backgrounds. This model is able to describe well the features of the experimental data and enables studies of the 
decay and other processes with high precision. We also measure the radio-purity of the LiMoO crystals which are found to be sufficient for the CUPID goals. Finally, we also obtain a background index in the region of interest of 3.7 
(stat)
(syst) 
counts/
the lowest in a bolometric decay experiment.
© The Author(s) 2023
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Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development.
