TY  - JOUR
AU  - NEXT Collaboration (Martinez-Lema, G. et al
AU  - Benlloch-Rodriguez, J. M.
AU  - Carcel, S.
AU  - Carrion, J. V.
AU  - Diaz, J.
AU  - Felkai, R.
AU  - Kekic, M.
AU  - Lopez-March, N.
AU  - Martin-Albo, J.
AU  - Martinez, A.
AU  - Martinez-Vara, M.
AU  - Muñoz Vidal, J.
AU  - Novella, P.
AU  - Palmeiro, B.
AU  - Querol, M.
AU  - Renner, J.
AU  - Romo-Luque, C.
AU  - Sorel, M.
AU  - Uson, A.
AU  - Yahlali, N.
PY  - 2021
DA  - 2021//
TI  - Sensitivity of the NEXT experiment to Xe-124 double electron capture
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 203
EP  - 25pp
VL  - 02
IS  - 2
PB  - Springer
KW  - Dark Matter and Double Beta Decay (experiments)
AB  - 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 nu EC EC) has been predicted for a number of isotopes, but only observed in Kr-78, Ba-130 and, recently, Xe-124. 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 nu EC EC. Here we report on the current sensitivity of the NEXT-White detector to Xe-124 2 nu EC EC and on the extrapolation to NEXT-100. Using simulated data for the 2 nu EC EC signal and real data from NEXT-White operated with Xe-124-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 Xe-124 and for a 5-year run, a sensitivity to the 2 nu EC EC half-life of 6 x 10(22) y (at 90% confidence level) or better can be reached.
SN  - 1029-8479
UR  - https://arxiv.org/abs/2006.07320
UR  - https://doi.org/10.1007/JHEP02(2021)203
DO  - 10.1007/JHEP02(2021)203
LA  - English
N1  - WOS:000624564800002
ID  - NEXTCollaborationMartinez-Lema_etal2021
ER  -