The background model of the CUPID-Mo $$0\nu \beta \beta $$ experiment

Augier, C.; Barabash, A. S.; Bellini, F.; Benato, G.; Beretta, M.; Berg??, L.; Billard, J.; Borovlev, Yu. A.; Cardani, L.; Casali, N.; Cazes, A.; Celi, E.; Chapellier, M.; Chiesa, D.; Dafinei, I.; Danevich, F. A.; De Jesus, M.; De Marcillac, P.; Dixon, T.; Dumoulin, L.; Eitel, K.; Ferri, F.; Fujikawa, B. K.; Gascon, J.; Gironi, L.; Giuliani, A.; Grigorieva, V. D.; Gros, M.; Helis, D. L.; Huang, H. Z.; Huang, R.; Imbert, L.; Johnston, J.; Juillard, A.; Khalife, H.; Kleifges, M.; Kobychev, V. V.; Kolomensky, Yu. G.; Konovalov, S. I.; Kotila, J.; Loaiza, P.; Ma, L.; Makarov, E. P.; Mariam, R.; Marini, L.; Marnieros, S.; Navick, X. -F.; Nones, C.; Norman, E. B.; Olivieri, E.; Ouellet, J. L.; Pagnanini, L.; Pattavina, L.; Paul, B.; Pavan, M.; Peng, H.; Pessina, G.; Pirro, S.; Poda, D. V.; Polischuk, O. G.; Pozzi, S.; Previtali, E.; Redon, Th.; Rojas, A.; Rozov, S.; Sanglard, V.; Scarpaci, J. A.; Schmidt, B.; Shen, Y.; Shlegel, V. N.; Singh, V.; Tomei, C.; Tretyak, V. I.; Umatov, V. I.; Vagneron, L.; Vel??zquez, M.; Welliver, B.; Winslow, L.; Xue, M.; Yakushev, E.; Zarytskyy, M.; Zolotarova, A. S.

doi:10.1140/epjc/s10052-023-11830-2

CUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation 0 nu beta beta decay experiment, CUPID. It consisted of an array of 20 enriched Li-2 (MoO4)-Mo-100 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 2 nu beta beta decay and other processes with high precision. We also mea sure the radio-purity of the Li-2 (MoO4)-Mo-100 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 (+0.9)(-0.8) (stat)(-0.7)(+1.5) (syst) x10(-3) counts/ Delta E-FWHM/moliso/year, the lowest in a bolometric 0 nu beta beta decay experiment.

The background model of the CUPID-Mo $$0\nu \beta \beta $$ experiment / Augier, C., Barabash, A.S., Bellini, F., Benato, G., Beretta, M., Berg??, L., Billard, J., Borovlev, Yu.A., Cardani, L., Casali, N., Cazes, A., Celi, E., Chapellier, M., Chiesa, D., Dafinei, I., Danevich, F.A., De Jesus, M., de Marcillac, P., Dixon, T., Dumoulin, L., et al.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 83:7(2023). [10.1140/epjc/s10052-023-11830-2]