scholarly journals An improved half-life limit of the double beta decay of 94Zr into the excited state of 94Mo

2018 ◽  
Vol 45 (7) ◽  
pp. 075104 ◽  
Author(s):  
N Dokania ◽  
D Degering ◽  
B Lehnert ◽  
V Nanal ◽  
K Zuber
2017 ◽  
Vol 53 (4) ◽  
Author(s):  
N. Dokania ◽  
V. Nanal ◽  
G. Gupta ◽  
S. Pal ◽  
R. G. Pillay ◽  
...  

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
M. Laubenstein ◽  
B. Lehnert ◽  
S. S. Nagorny

Abstract As one of the primordial radioactive isotopes, $$^{232}\mathrm{Th}$$232Th mainly undergoes $$\alpha $$α-decay with a half-life of $$1.402\cdot 10^{10}$$1.402·1010 years. However, it is also one of 35 double beta decay candidates in which the single $$\beta $$β-decay is forbidden or strongly suppressed. 181 mg of thorium contained in a gas mantle were measured in a HPGe well-detector at the Gran Sasso Underground Laboratory with a total exposure of 3.25 g$$\times $$×d. We obtain half-life limits on all double beta decay modes of $$^{232}\mathrm{Th}$$232Th to excited states of $$^{232}\mathrm{U}$$232U on the order of $$10^{11-15}$$1011-15 years. For the most likely transition into the 0$$^+_1$$1+ state we find a lower half-life limit of $$6.7\cdot 10^{14}$$6.7·1014 years (90% C.I.). These are the first constraints on double beta decay excited state transition in $$^{232}\mathrm{Th}$$232Th.


1996 ◽  
Vol 48 (1-3) ◽  
pp. 213-215 ◽  
Author(s):  
A. Balysh ◽  
A. De Silva ◽  
V.I. Lebedev ◽  
K. Lou ◽  
M.K. Moe ◽  
...  

2004 ◽  
Vol 67 (6) ◽  
pp. 1216-1219 ◽  
Author(s):  
A. S. Barabash ◽  
F. Hubert ◽  
Ph. Hubert ◽  
V. I. Umatov

2018 ◽  
Vol 33 (09) ◽  
pp. 1843004 ◽  
Author(s):  
◽  
M. Agostini ◽  
A. M. Bakalyarov ◽  
M. Balata ◽  
I. Barabanov ◽  
...  

The GERmanium Detector Array (GERDA) is a low background experiment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN designed to search for the rare neutrinoless double beta decay ([Formula: see text]) of [Formula: see text]Ge. In the first phase (Phase I) of the experiment, high purity germanium diodes were operated in a “bare” mode and immersed in liquid argon. The overall background level of [Formula: see text] was a factor of ten better than those of its predecessors. No signal was found and a lower limit was set on the half-life for the [Formula: see text] decay of [Formula: see text]Ge [Formula: see text] yr (90% CL), while the corresponding median sensitivity was [Formula: see text] yr (90% CL). A second phase (Phase II) started at the end of 2015 after a major upgrade. Thanks to the increased detector mass and performance of the enriched germanium diodes and due to the introduction of liquid argon instrumentation techniques, it was possible to reduce the background down to [Formula: see text]. After analyzing 23.2 kg[Formula: see text]⋅[Formula: see text]yr of these new data no signal was seen. Combining these with the data from Phase I a stronger half-life limit of the [Formula: see text]Ge [Formula: see text] decay was obtained: [Formula: see text] yr (90% CL), reaching a sensitivity of [Formula: see text] yr (90% CL). Phase II will continue for the collection of an exposure of 100 kg[Formula: see text]yr. If no signal is found by then the GERDA sensitivity will have reached [Formula: see text] yr for setting a 90% CL. limit. After the end of GERDA Phase II, the flagship experiment for the search of [Formula: see text] decay of [Formula: see text]Ge will be LEGEND. LEGEND experiment is foreseen to deploy up to 1-ton of [Formula: see text]Ge. After ten years of data taking, it will reach a sensitivity beyond 10[Formula: see text] yr, and hence fully cover the inverted hierarchy region.


Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 10 ◽  
Author(s):  
Alessio Caminata ◽  
Douglas Adams ◽  
Chris Alduino ◽  
Krystal Alfonso ◽  
Frank Avignone ◽  
...  

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO 2 crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total TeO 2 exposure of 86.3 kg yr , characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts / ( keV kg yr ) . In this physics run, CUORE placed a lower limit on the decay half-life of neutrinoless double beta decay of 130 Te > 1.3 · 10 25 yr (90% C.L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the 130 Te 2 ν β β decay with a resulting half-life of T 1 / 2 2 ν = [ 7.9 ± 0.1 ( stat . ) ± 0.2 ( syst . ) ] × 10 20 yr which is the most precise measurement of the half-life and compatible with previous results.


Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 182
Author(s):  
Pierluigi Belli ◽  
R. Bernabei ◽  
V.B. Brudanin ◽  
F. Cappella ◽  
V. Caracciolo ◽  
...  

Studies on double beta decay processes in 106Cd were performed by using a cadmium tungstate scintillator enriched in 106Cd at 66% (106CdWO4) with two CdWO4 scintillation counters (with natural Cd composition). No effect was observed in the data that accumulated over 26,033 h. New improved half-life limits were set on the different channels and modes of the 106Cd double beta decay at level of limT1/2∼1020−1022 yr. The limit for the two neutrino electron capture with positron emission in 106Cd to the ground state of 106Pd, T1/22νECβ+≥2.1×1021 yr, was set by the analysis of the 106CdWO4 data in coincidence with the energy release 511 keV in both CdWO4 counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range T1/2∼1021−1022 yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of 106Pd is restricted at the level of T1/20ν2K≥2.9×1021 yr.


2009 ◽  
Author(s):  
A. S. Barabash ◽  
Osvaldo Civitarese ◽  
Ivan Stekl ◽  
Jouni Suhonen

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