Search for the double-beta decay of 82Se to the excited states of 82Kr with NEMO-3

Arnold, R; Augier, C; Barabash, A; Basharina-Freshville, A; Blondel, S; Blot, S; Bongrand, M; Boursette, D; Breier, R; Brudanin, V; Busto, J; Caffrey, A; Calvez, S; Cascella, M; Cerna, C; Cesar, J; Chapon, A; Chauveau, E; Chopra, A; Dawson, L; Duchesneau, D; Durand, D; Egorov, V; Eurin, G; Evans, J; Fajt, L; Filosofov, D; Flack, R; Garrido, X; Girard-Carillo, C; Gomez, H; Guillon, B; Guzowski, P; Hodak, R; Huber, A; Hubert, P; Hugon, C; Jullian, S; Klimenko, A; Kochetov, O; Konovalov, S; Kovalenko, V; Lalanne, D; Lang, K; Lemiere, Y; Le Noblet, T; Liptak, Z; Liu, X; Loaiza, P; Lutter, G; Macko, M; Macolino, C; Mamedov, F; Marquet, C; Mauger, F; Minotti, A; Morgan, B; Mott, J; Nemchenok, I; Nomachi, M; Nova, F; Nowacki, F; Ohsumi, H; Oliviero, G; Pahlka, R; Palusova, V; Patrick, C; Perrot, F; Pin, A; Piquemal, F; Povinec, P; Pridal, P; Ramachers, Y; Remoto, A; Reyss, J; Richards, B; Riddle, C; Rukhadze, E; Saakyan, R; Salazar, R; Sarazin, X; Sedgbeer, J; Shitov, Y; Simard, L; Simkovic, F; Smetana, A; Smolek, K; Smolnikov, A; Soldner-Rembold, S; Soule, B; Stekl, I; Suhonen, J; Sutton, C; Szklarz, G; Tedjditi, H; Thomas, J; Timkin, V; Torre, S; Tretyak, V; Tretyak, V; Umatov, V; Vanushin, I; Vilela, C; Vorobel, V; Waters, D; Xie, F; Zukauskas, A

doi:10.1016/j.nuclphysa.2020.121701

The double-beta decay of 82Se to the 01+ excited state of 82Kr has been studied with the NEMO-3 detector using 0.93 kg of enriched 82Se measured for 4.75 y, corresponding to an exposure of 4.42 kg⋅y. A dedicated analysis to reconstruct the γ-rays has been performed to search for events in the 2e2γ channel. No evidence of a 2νββ decay to the 01+ state has been observed and a limit of T1/22ν(Se82,0gs+→01+)>1.3×1021y at 90% CL has been set. Concerning the 0νββ decay to the 01+ state, a limit for this decay has been obtained with T1/20ν(Se82,0gs+→01+)>2.3×1022y at 90% CL, independently from the 2νββ decay process. These results are obtained for the first time with a tracko-calo detector, reconstructing every particle in the final state.

Arnold, R., Augier, C., Barabash, A., Basharina-Freshville, A., Blondel, S., Blot, S., et al. (2020). Search for the double-beta decay of 82Se to the excited states of 82Kr with NEMO-3. NUCLEAR PHYSICS. A, 996 [10.1016/j.nuclphysa.2020.121701].