Double-weak decays of and in the XENON1T and XENONnT experiments

Aprile, E.; Abe, K.; Agostini, F.; Ahmed Maouloud, S.; Alfonsi, M.; Althueser, L.; Andrieu, B.; Angelino, E.; Angevaare, J. R.; Antochi, V. C.; Martin, D. Ant??n.; Arneodo, F.; Baudis, L.; Baxter, A. L.; Bellagamba, L.; Biondi, R.; Bismark, A.; Brown, A.; Bruenner, S.; Bruno, G.; Budnik, R.; Cai, C.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Clark, M.; Colijn, A. P.; Conrad, J.; Cuenca-Garc??a, J. J.; Cussonneau, J. P.; D'Andrea, V.; Decowski, M. P.; Di Gangi, P.; Di Pede, S.; Di Giovanni, A.; Di Stefano, R.; Diglio, S.; Eitel, K.; Elykov, A.; Farrell, S.; Ferella, A. D.; Fischer, H.; Fulgione, W.; Gaemers, P.; Gaior, R.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Glade-Beucke, R.; Grandi, L.; Grigat, J.; Guida, M.; Higuera, A.; Hils, C.; Hoetzsch, L.; Howlett, J.; Iacovacci, M.; Itow, Y.; Jakob, J.; Joerg, F.; Joy, A.; Kato, N.; Kara, M.; Kavrigin, P.; Kazama, S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang, R. F.; Levinson, L.; Li, I.; Li, S.; Liang, S.; Lindemann, S.; Lindner, M.; Liu, K.; Loizeau, J.; Lombardi, F.; Long, J.; Lopes, J. A. M.; Ma, Y.; Macolino, C.; Mahlstedt, J.; Mancuso, A.; Manenti, L.; Manfredini, A.; Marignetti, F.; Undagoitia, T. Marrod??n.; Martens, K.; Masbou, J.; Masson, D.; Masson, E.; Mastroianni, S.; Messina, M.; Miuchi, K.; Mizukoshi, K.; Molinario, A.; Moriyama, S.; Mor??, K.; Mosbacher, Y.; Murra, M.; M??ller, J.; Ni, K.; Oberlack, U.; Paetsch, B.; Palacio, J.; Peres, R.; Pienaar, J.; Pierre, M.; Pizzella, V.; Plante, G.; Qi, J.; Qin, J.; Ram??rez Garc??a, D.; Reichard, S.; Rocchetti, A.; Rupp, N.; Sanchez, L.; Dos Santos, J. M. F.; Sarnoff, I.; Sartorelli, G.; Schreiner, J.; Schulte, D.; Schulte, P.; Schulze Ei??ing, H.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Semeria, F.; Shagin, P.; Shi, S.; Shockley, E.; Silva, M.; Simgen, H.; Takeda, A.; Tan, P. -L.; Terliuk, A.; Thers, D.; Toschi, F.; Trinchero, G.; Tunnell, C.; T??nnies, F.; Valerius, K.; Volta, G.; Wei, Y.; Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; Wolf, T.; Xu, Z.; Yamashita, M.; Yang, L.; Ye, J.; Yuan, L.; Zavattini, G.; Zerbo, S.; Zhong, M.; Zhu, T.

doi:10.1103/physrevc.106.024328

We present results on the search for two-neutrino double-electron capture (2νECEC) of 124Xe and neutrinoless double-β decay (0νββ) of 136Xe in XENON1T. We consider captures from the K shell up to the N shell in the 2νECEC signal model and measure a total half-life of T2νECEC1/2=(1.1±0.2stat±0.1sys)×1022yr with a 0.87kgyr isotope exposure. The statistical significance of the signal is 7.0σ. We use XENON1T data with 36.16kgyr of 136Xe exposure to search for 0νββ. We find no evidence of a signal and set a lower limit on the half-life of T0νββ1/2>1.2×1024yrat90%CL. This is the best result from a dark matter detector without an enriched target to date. We also report projections on the sensitivity of XENONnT to 0νββ. Assuming a 275kgyr 136Xe exposure, the expected sensitivity is T0νββ1/2>2.1×1025yrat90%CL, corresponding to an effective Majorana mass range of ⟨mββ⟩<(0.19–0.59)eV/c2.

Double-weak decays of and in the XENON1T and XENONnT experiments / Aprile, E., Abe, K., Agostini, F., Ahmed Maouloud, S., Alfonsi, M., Althueser, L., Andrieu, B., Angelino, E., Angevaare, J.R., Antochi, V.C., Martin, D.Ant??n., Arneodo, F., Baudis, L., Baxter, A.L., Bellagamba, L., Biondi, R., Bismark, A., Brown, A., Bruenner, S., Bruno, G., et al.. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 106:2(2022), p. 024328. [10.1103/physrevc.106.024328]