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

R. Arnold (1) , C. Augier (2) , A.S. Barabash , A. Basharina-Freshville , S. Blondel (2) , S. Blot , M. Bongrand (2) , D. Boursette (2) , R. Breier , V. Brudanin , J. Busto (3) , A.J. Caffrey , S. Calvez (2) , M. Cascella (2) , C. Cerna (4) , J.P. Cesar , A. Chapon (5) , E. Chauveau (4) , A. Chopra , L. Dawson , D. Duchesneau (6) , D. Durand (5) , V. Egorov , G. Eurin (2) , J.J. Evans , L. Fajt , D. Filosofov , R. Flack , X. Garrido (2) , C. Girard-Carillo (2) , H. Gómez (2) , B. Guillon (5) , P. Guzowski , R. Hodák , A. Huber (4) , P. Hubert (4) , C. Hugon (4) , S. Jullian (2) , A. Klimenko , O. Kochetov , S.I. Konovalov , V. Kovalenko , D. Lalanne (2) , K. Lang , Y. Lemière (5) , T. Le Noblet (6) , Z. Liptak , X.R. Liu , P. Loaiza (2) , G. Lutter (4) , M. Macko , C. Macolino (2) , F. Mamedov , C. Marquet (4) , F. Mauger (5) , A. Minotti (6) , B. Morgan , J. Mott , I. Nemchenok , M. Nomachi , F. Nova , F. Nowacki (1) , H. Ohsumi , G. Oliviéro (5) , R.B. Pahlka , V. Palusova (4) , C. Patrick , F. Perrot (4) , A. Pin (4) , F. Piquemal (4, 7) , P. Povinec , P. Přidal , Y.A. Ramachers , A. Remoto (6) , J.L. Reyss (8) , B. Richards , C.L. Riddle , E. Rukhadze , R. Saakyan , R. Salazar , X. Sarazin (2) , J. Sedgbeer , Yu. Shitov , L. Simard (2, 9) , F. Šimkovic , A. Smetana , K. Smolek , A. Smolnikov , S. Söldner-Rembold , B. Soulé (4) , I. Štekl , J. Suhonen , C.S. Sutton , G. Szklarz (2) , H. Tedjditi (3) , J. Thomas , V. Timkin , S. Torre , Vl.I. Tretyak , V.I. Tretyak , V.I. Umatov , I. Vanushin , C. Vilela , V. Vorobel , D. Waters , F. Xie , A. Žukauskas

1 IPHC - Institut Pluridisciplinaire Hubert Curien
2 LAL - Laboratoire de l'Accélérateur Linéaire
3 CPPM - Centre de Physique des Particules de Marseille
4 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
5 LPCC - Laboratoire de physique corpusculaire de Caen
6 LAPP - Laboratoire d'Annecy de Physique des Particules
7 LSM - UMR 6417 - Laboratoire Souterrain de Modane
8 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
9 IUF - Institut universitaire de France

The double-beta decay of 82Se to the 0+1 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 gamma-rays has been performed to search for events in the 2e2g channel. No evidence of a 2nbb decay to the 0+1 state has been observed and a limit of T2n 1/2(82Se; 0+gs -> 0+1) > 1.3 1021 y at 90% CL has been set. Concerning the 0nbb decay to the 0+1 state, a limit for this decay has been obtained with T0n 1/2(82Se; 0+g s -> 0+1) > 2.3 1022 y at 90% CL, independently from the 2nbb decay process. These results are obtained for the first time with a tracko-calo detector, reconstructing every particle in the final state.

Mots clés: double-beta decay; selenium: nuclide; krypton: nuclide; nucleus: excited state; gamma ray: particle identification; Neutrino Ettore Majorana Observatory; experimental results

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique des Hautes Energies - Expérience [hep-ex]

R. Arnold, C. Augier, A.S. Barabash, A. Basharina-Freshville, S. Blondel, et al.. Search for the double-beta decay of $^{82}$Se to the excited states of $^{82}$Kr with NEMO-3. Nuclear Physics A, 2020, 996, pp.121701. ⟨10.1016/j.nuclphysa.2020.121701⟩. ⟨hal-02467317⟩