Sensitivity of the NEXT experiment to Xe-124 double electron capture

Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite different, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-al...

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Autores: Martínez-Lema, G., Martínez-Vara, M., Sorel, M., Adams, C., Álvarez, V., Arazi, L., Arnquist, I.J., Azevedo, C.D.R., Bailey, K., Ballester, F., Benlloch-Rodríguez, J.M., Borges, F.I.G.M., Byrnes, N., Cárcel, S., Carrión, J.V., Cebrián, S., Church, E., Conde, C.A.N., Contreras, T., Díaz, G., Díaz, J., Diesburg, M., Escada, J., Esteve, R., Felkai, R., Fernandes, A.F.M., Fernandes, L.M.P., Ferrario, P., Ferreira, A.L., Freitas, E.D.C., Generowicz, J., Ghosh, S., Goldschmidt, A., Gómez-Cadenas, J.J., González-Díaz, D., Guenette, R., Gutiérrez, R.M., Haefner, J., Hafidi, K., Hauptman, J., Henriques, C.A.O., Hernando Morata, J.A., Herrero, P., Herrero, V., Ifergan, Y., Johnston, S., Jones, B.J.P., Kekic, M., Labarga, L., Laing, A., Lebrun, P., López-March, N., Losada, M., Mano, R.D.P., Martín-Albo, J., Martínez, A., McDonald, A.D., Monrabal, F., Monteiro, C.M.B., Mora, F.J., Muñoz Vidal, J., Novella, P., Nygren, D.R., Palmeiro, B., Para, A., Pérez, J., Querol, M., Redwine, A.B., Renner, J., Repond, J., Riordan, S., Ripoll, L., Rodríguez García, Y., Rodríguez, J., Rogers, L., Romeo, B., Romo-Luque, C., Santos, F.P., dos Santos, J.M.F., Simón, A., Sofka, C., Stiegler, T., Toledo, J.F., Torrent, J., Usón, A., Veloso, J.F.C.A., Webb, R., Weiss-Babai, R., White, J.T., Woodruff, K., Yahlali, N., The, NEXT, collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Zaragoza
Repositorio:Zaguán. Repositorio Digital de la Universidad de Zaragoza
OAI Identifier:oai:zaguan.unizar.es:102139
Acceso en línea:http://zaguan.unizar.es/record/102139
Access Level:acceso abierto
Descripción
Sumario:Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite different, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-allowed two-neutrino double electron capture (2¿EC EC) has been predicted for a number of isotopes, but only observed in 78Kr, 130Ba and, recently, 124Xe. The sensitivity to this decay establishes a benchmark for the ultimate experimental goal, namely the potential to discover also the lepton-number-violating neutrinoless version of this process, 0¿EC EC. Here we report on the current sensitivity of the NEXT-White detector to 124Xe 2¿EC EC and on the extrapolation to NEXT-100. Using simulated data for the 2¿EC EC signal and real data from NEXT-White operated with 124Xe-depleted gas as background, we define an optimal event selection that maximizes the NEXT-White sensitivity. We estimate that, for NEXT-100 operated with xenon gas isotopically enriched with 1 kg of 124Xe and for a 5-year run, a sensitivity to the 2¿EC EC half-life of 6 × 1022 y (at 90% confidence level) or better can be reached. [Figure not available: see fulltext.]