New limit on neutrinoless double β decay inXe136with a time projection chamber

Abstract

A xenon time projection chamber with an active volume of 207 L has been built to study neutrinoless double p decay in '^^Xe. Data were taken in the Gotthard Underground Laboratory, with 5 atm of xenon enriched to 62.5% in '^^Xe. From 3380 h of data, no evidence has been found for the Ov O"*"-* 0"^ transition. Half-life limits of r?/2 > 2.5(4.9) x 10^^ yr in the mass-mechanism mode and T'^/2 > 1.7(3.2) X 10^^ yr in the right-handed-current mode, at the 90(68)% C.L., were derived. An upper limit for the Majorana neutrino mass parameter was deduced.

PandaX-III: Searching for Neutrinoless Double Beta Decay with High Pressure $^{136}$Xe Gas Time Projection Chambers

“…To search for the NLDBD mode of 136 Xe, PandaX-III experiment will use a technology of highpressure low-background gas TPCs which was developed for the experiments in the early 1990's [26,27,28] and recently for the NEXT experiment [25], while there has been a little follow up during in-between 20 years. This type of experiment is challenging for a number of reasons.…”

“…There are several approaches to this problem. The classical solution is to use high-purity copper, as in the Gotthard experiment [54,26]. For high pressure vessel, large quantity of OFHC copper is needed for the mechanical strength.…”

Main features of detectors and isotopes to investigate double beta decay with increased sensitivity

“…The first ββ decay measurements with 136 Xe were performed using a scintillation detector based on liquid Xe [111] and a high-pressure gas ionization chamber [112]. In the early 90's, measurements using a proportional counter [113] and a gas TPC [114,115] were realised. In 2000, the EXO experiment [116] was presented in which it was proposed to register all the products of the ββ-decay of 136 Xe (including registration of the + Ba ion, the daughter nucleus after the ββ decay of 136 Xe) using gas (or liquid) TPC 3 .…”