New measurement of double-β decays of Mo100 to excited states of Ru100 with the CUPID-Mo experiment

Augier, C.; Barabash, A. S.; Bellini, F.; Benato, G.; Beretta, M.; Bergé, L.; Billard, J.; Borovlev, Yu. A.; Cardani, L.; Casali, N.; Cazes, A.; Chapellier, M.; Chiesa, D.; Dafinei, I.; Danevich, F. A.; De Jesus, M.; 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.; de Marcillac, 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.; Velázquez, M.; Welliver, B.; Winslow, L.; Xue, M.; Yakushev, E.; Zarytskyy, M.; Zolotarova, A. S.

doi:10.1103/PhysRevC.107.025503

The CUPID-Mo experiment, located at the Laboratoire Souterrain de Modane (France), was a demonstrator experiment for CUPID. It consisted of an array of 20 Li2 100MoO4 (LMO) calorimeters, each equipped with a Ge light detector for particle identification. In this work, we present the result of a search for two-neutrino and neutrinoless double-β decays of 100Mo to the first 0+ and 2+ excited states of 100Ru using the full CUPID-Mo exposure (2.71 kg yr of LMO). We measure the half-life of 2νββ decay to the 0+ state as T 2ν→01+ = (7.5 ± 1 1/2 0.8 (stat.) +0.4 (syst.)) × 1020 yr. The bolometric technique enables measurement of the electron energies as well −0.3 as the γ rays from nuclear deexcitation and this allows us to set new limits on the two-neutrino decay to the 21+ state of T 2ν→21+ > 4.4 × 1021 yr (90% c.i.) and on the neutrinoless modes of T 0ν→21+ > 2.1 × 1023 yr (90% c.i.), T 0ν→01+ > 1.2 × 1023 yr (90% c.i.). Information on the electrons’ spectral shape is obtained, which allows us to 1/2 make the first comparison of the single and higher state dominance 2νββ decay models for the 01+ excited state of 100Ru.

New measurement of double-β decays of Mo100 to excited states of Ru100 with the CUPID-Mo experiment / Augier, C.; Barabash, A. S.; Bellini, F.; Benato, G.; Beretta, M.; Bergé, L.; Billard, J.; Borovlev, Yu. A.; Cardani, L.; Casali, N.; Cazes, A.; Chapellier, M.; Chiesa, D.; Dafinei, I.; Danevich, F. A.; De Jesus, M.; 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.; de Marcillac, 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.; Velázquez, M.; Welliver, B.; Winslow, L.; Xue, M.; Yakushev, E.; Zarytskyy, M.; Zolotarova, A. S.. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 107:2(2023). [10.1103/PhysRevC.107.025503]