We report the measurement of the two-neutrino double-beta ($2\nu\beta\beta$) decay of $^{100}$Mo to the ground state of $^{100}$Ru using lithium molybdate (\crystal) scintillating bolometers. The ...detectors were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory. From a total exposure of $42.235$ kg$\times$d, the half-life of $^{100}$Mo is determined to be $T_{1/2}^{2\nu}=7.12^{+0.18}_{-0.14}\,\mathrm{(stat.)}\pm0.10\,\mathrm{(syst.)}\times10^{18}$ years. This is the most accurate determination of the $2\nu\beta\beta$ half-life of $^{100}$Mo to date. We also confirm, with the statistical significance of $>3\sigma$, that the single-state dominance model of the $2\nu\beta\beta$ decay of $^{100}$Mo is favored over the high-state dominance model.
Optimization of the first CUPID detector module Augier, C.; Balata, M.; Barabash, A. S. ...
The European physical journal. C, Particles and fields,
09/2022, Letnik:
82, Številka:
9
Journal Article
Recenzirano
Odprti dostop
CUPID will be a next generation experiment searching for the neutrinoless double
β
decay, whose discovery would establish the Majorana nature of the neutrino. Based on the experience achieved with ...the CUORE experiment, presently taking data at LNGS, CUPID aims to reach a background free environment by means of scintillating Li
2
100
MoO
4
crystals coupled to light detectors. Indeed, the simultaneous heat and light detection allows us to reject the dominant background of
α
particles, as proven by the CUPID-0 and CUPID-Mo demonstrators. In this work we present the results of the first test of the CUPID baseline module. In particular, we propose a new optimized detector structure and light sensors design to enhance the engineering and the light collection, respectively. We characterized the heat detectors, achieving an energy resolution of (5.9 ± 0.2) keV FWHM at the
Q
-value of
100
Mo (about 3034 keV). We studied the light collection of the baseline CUPID design with respect to an alternative configuration which features gravity-assisted light detectors’ mounting. In both cases we obtained an improvement in the light collection with respect to past measures and we validated the particle identification capability of the detector, which ensures an
α
particle rejection higher than 99.9%, fully satisfying the requirements for CUPID.
Results from a prototype TES detector for the Ricochet experiment Augier, C.; Baulieu, G.; Belov, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2023, Letnik:
1057
Journal Article
Recenzirano
Odprti dostop
Coherent elastic neutrino-nucleus scattering (CEνNS) offers valuable sensitivity to physics beyond the Standard Model. The Ricochet experiment will use cryogenic solid-state detectors to perform a ...precision measurement of the CEνNS spectrum induced by the high neutrino flux from the Institut Laue-Langevin nuclear reactor. The experiment will employ an array of detectors, each with a mass of ∼30 g and a targeted energy threshold of 50 eV. Nine of these detectors (the “Q-Array”) will be based on a novel Transition-Edge Sensor (TES) readout style, in which the TES devices are thermally coupled to the absorber using a gold wire bond. We present initial characterization of a Q-Array-style detector using a 1 gram silicon absorber, obtaining a baseline root-mean-square resolution of less than 40 eV.
The EDELWEISS-II Collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The ...combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of γ-induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4×10−8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.
The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double
β
decay experiment SuperNEMO is ...discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double
β
decay by measuring the decay half-life and the electron angular and energy distributions.
The CUPID Collaboration is designing a tonne-scale, background-free detector to search for double beta decay with sufficient sensitivity to fully explore the parameter space corresponding to the ...inverted neutrino mass hierarchy scenario. One of the CUPID demonstrators, CUPID-Mo, has proved the potential of enriched Li
2
100
MoO
4
crystals as suitable detectors for neutrinoless double beta decay search. In this work, we characterised cubic crystals that, compared to the cylindrical crystals used by CUPID-Mo, are more appealing for the construction of tightly packed arrays. We measured an average energy resolution of (
6.7
±
0.6
) keV FWHM in the region of interest, approaching the CUPID target of 5 keV FWHM. We assessed the identification of
α
particles with and without a reflecting foil that enhances the scintillation light collection efficiency, proving that the baseline design of CUPID already ensures a complete suppression of this
α
-induced background contribution. We also used the collected data to validate a Monte Carlo simulation modelling the light collection efficiency, which will enable further optimisations of the detector.
The future
Ricochet
experiment aims to search for new physics in the electroweak sector by measuring the Coherent Elastic Neutrino-Nucleus Scattering process from reactor antineutrinos with high ...precision down to the sub-100 eV nuclear recoil energy range. While the
Ricochet
collaboration is currently building the experimental setup at the reactor site, it is also finalizing the cryogenic detector arrays that will be integrated into the cryostat at the Institut Laue Langevin in early 2024. In this paper, we report on recent progress from the Ge cryogenic detector technology, called the CryoCube. More specifically, we present the first demonstration of a 30 eVee (electron equivalent) baseline ionization resolution (RMS) achieved with an early design of the detector assembly and its dedicated High Electron Mobility Transistor (HEMT) based front-end electronics with a total input capacitance of about 40 pF. This represents an order of magnitude improvement over the best ionization resolutions obtained on similar phonon-and-ionization germanium cryogenic detectors from the EDELWEISS and SuperCDMS dark matter experiments, and a factor of three improvement compared to the first fully-cryogenic HEMT-based preamplifier coupled to a CDMS-II germanium detector with a total input capacitance of 250 pF. Additionally, we discuss the implications of these results in the context of the future
Ricochet
experiment and its expected background mitigation performance.
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