Open AccessMeasurement of the 136-Xe ββ2υ half-life in NEXT-White
Author(s) -
A. Usón
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2156/1/012122
Subject(s) - neutrino , xenon , physics , nuclear physics , detector , robustness (evolution) , bar (unit) , double beta decay , nuclear engineering , computational physics , optics , engineering , biochemistry , chemistry , meteorology , gene
The NEXT (Neutrino Experiment with a Xenon TPC) collaboration searches for the neutrino-less double beta decay ( 0υββ ) of 136 Xe at the Laboratorio Subterráneo de Canfranc (LSC). A first large-scale prototype of a high-pressure Xenon gas electroluminescent TPC, NEXT-White, operated at the LSC from 2016 to 2021. In this analysis, the measurement of the half-life of the two-neutrino mode of the double beta decay ( 2νυβ ) will be presented. For this measurement, two novel techniques in the field have been used: a highly refined topological reconstruction of events that improves the background rejection, and a direct subtraction of the ββ backgrounds, measured with 136 Xe-depleted data. These techniques allow for background-model-dependent and background-model-independent results, demonstrating the robustness of the 2νυβ half-life measurement and the unique capabilities of NEXT. The final value presented corresponds to a half-life of T- 2υ 1/2 = 2.34+0’® 0 (stat)-0’ 3 7(sys) x 10 21 year. After the completion of the NEXT-White programme, the NEXT-100 apparatus will start its commissioning at the second half of 2022. Holding 100 kg of 136 Xe at 15 bar, this detector will perform the first competitive 0νυβ search within the NEXT roadmap. As validated with NEXT-White, NEXT- 100 will set a limit in m-ββ of 70-130 meV after 5 years of data taking.