Ricochet Progress and Status Collaboration, Ricochet; Beaulieu, G; Belov, V ...
arXiv.org,
11/2021
Paper, Journal Article
Odprti dostop
We present an overview of recent progress towards the Ricochet coherent elastic neutrino nucleus scattering CE\(\nu\)NS experiment. The ILL research reactor in Grenoble, France has been selected as ...the experiment site, after in situ studies of vibration and particle backgrounds. We present background rate estimates specific to that site, along with descriptions of the planned CryoCube and Q-Array detector payloads.
The CUPID-Mo experiment at the Laboratoire Souterrain de Modane (France) is a demonstrator for CUPID, the next-generation ton-scale cryogenic \(0\nu\beta\beta\) experiment. It consists of a 4.2 kg ...array of 20 enriched Li$_{2}$$^{100}\(MoO\)_4\( scintillating bolometers to search for the lepton number violating process of \)0\nu\beta\beta\( decay in \)^{100}\(Mo. With more than one year of operation (2.16 kg\)\times\(yr of physics data), no event in the region of interest and hence no evidence for \)0\nu\beta\beta\( is observed. We report a new limit on the half-life of \)0\nu\beta\beta\( decay in \)^{100}\(Mo of \)T_{1/2} > 1.5 \times 10^{24}\,\(yr at 90 % C.I. The limit corresponds to an effective Majorana neutrino mass \)\langle m_{\beta\beta} \rangle\( \)<\( (0.31--0.54)\)\,$eV, dependent on the nuclear matrix element in the light Majorana neutrino exchange interpretation.
CUPID-Mo is a cryogenic detector array designed to search for neutrinoless double-beta decay (\(0\nu\beta\beta\)) of \(^{100}\)Mo. It uses 20 scintillating \(^{100}\)Mo-enriched Li\(_2\)MoO\(_4\) ...bolometers instrumented with Ge light detectors to perform active suppression of \(\alpha\) backgrounds, drastically reducing the expected background in the \(0\nu\beta\beta\) signal region. As a result, pileup events and small detector instabilities that mimic normal signals become non-negligible potential backgrounds. These types of events can in principle be eliminated based on their signal shapes, which are different from those of regular bolometric pulses. We show that a purely data-driven principal component analysis based approach is able to filter out these anomalous events, without the aid of detector response simulations.
A scintillating bolometer based on a large cubic Li$_{2}$$^{100}$MoO$_4$
crystal (45 mm side) and a Ge wafer (scintillation detector) has been operated
in the CROSS cryogenic facility at the Canfranc ...underground laboratory in
Spain. The dual-readout detector is a prototype of the technology that will be
used in the next-generation $0\nu2\beta$ experiment CUPID. The measurements
were performed at 18 and 12 mK temperature in a pulse tube dilution
refrigerator. This setup utilizes the same technology as the CUORE cryostat
that will host CUPID and so represents an accurate estimation of the expected
performance. The Li$_{2}$$^{100}$MoO$_4$ bolometer shows a high energy
resolution of 6 keV FWHM at the 2615 keV $\gamma$ line. The detection of
scintillation light for each event triggered by the Li$_{2}$$^{100}$MoO$_4$
bolometer allowed for a full separation ($\sim$8$\sigma$) between
$\gamma$($\beta$) and $\alpha$ events above 2 MeV. The Li$_{2}$$^{100}$MoO$_4$
crystal also shows a high internal radiopurity with $^{228}$Th and $^{226}$Ra
activities of less than 3 and 8 $\mu$Bq/kg, respectively. Taking also into
account the advantage of a more compact and massive detector array, which can
be made of cubic-shaped crystals (compared to the cylindrical ones), this test
demonstrates the great potential of cubic Li$_{2}$$^{100}$MoO$_4$ scintillating
bolometers for high-sensitivity searches for the $^{100}$Mo $0\nu2\beta$ decay
in CROSS and CUPID projects.
The CUPID Collaboration is designing a tonne-scale, background-free detector
to search for double beta decay with sufficient sensitivity to fully explore
the parameter space corresponding to the ...inverted neutrino mass hierarchy
scenario. One of the CUPID demonstrators, CUPID-Mo, has proved the potential of
enriched Li$_{2}$$^{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$\pm$0.6) keV FWHM in the region of interest,
approaching the CUPID target of 5 keV FWHM. We assessed the identification of
$\alpha$ 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 $\alpha$-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 RICOCHET reactor neutrino observatory is planned to be installed at the Laue Langevin Institute (ILL) starting mid-2022. Its scientific goal is to perform a low-energy and high precision ...measurement of the coherent elastic neutrino-nucleus scattering (CE\(\nu\)NS) spectrum in order to explore exotic physics scenarios. RICOCHET will host two cryogenic detector arrays: the CryoCube (Ge target) and the Q-ARRAY (Zn target), operated at 10 mK. The 1 kg Ge CryoCube will consist of 27 Ge crystals instrumented with NTD-Ge thermal sensors and charge collection electrodes for a simultaneous heat and ionization readout to reject the electromagnetic backgrounds (gamma, beta, x-rays). We present the status of its front-end electronics. The first stage of amplification is made of High Electron Mobility Transistor (HEMT) developed by CNRS/C2N laboratory, optimized to achieve ultra-low noise performance at 1K with a dissipation as low as 15 \(\mu\)W per channel. Our noise model predicts that 10 eV heat and 20 eVee RMS baseline resolutions are feasible with a high dynamic range for the deposited energy (up to 10 MeV) thanks to loop amplification schemes. Such resolutions are mandatory to have a high discrimination power between nuclear and electron recoils at the lowest energies.
The Magnificent CE$\nu$NS Workshop (2018) was held November 2 & 3 of 2018 on
the University of Chicago campus and brought together theorists,
phenomenologists, and experimentalists working in ...numerous areas but sharing a
common interest in the process of coherent elastic neutrino-nucleus scattering
(CE$\nu$NS). This is a collection of abstract-like summaries of the talks given
at the meeting, including links to the slides presented. This document and the
slides from the meeting provide an overview of the field and a snapshot of the
robust CE$\nu$NS-related efforts both planned and underway.
Background Allergic sensitization is increased among offspring of sensitized parents. Objective We sought to evaluate whether 18-year-old offspring are likely to have the same allergic sensitizations ...as their parents. Methods Eighteen-year-old participants in an unselected birth cohort and their parents were tested for total and increased (>0.35 kU/L) levels of allergen-specific IgE to 6 allergens: Dermatophagoides farinae , dog, cat, grass, ragweed, and Alternaria alternata. Results In 316 parent-teen triads parental sensitization to any of 6 allergens was associated with teen sensitization to any of those same allergens. An increased risk of matched sensitization (ie, a teen has an increased risk of being sensitized to the same specific allergen as their parent) was found after adjusting for the spouse's sensitivities and adjusting for other allergens (ie, the parent had an allergic sensitization but not to the particular allergen under analysis). Risk of maternal matched sensitization with their teen to cat (adjusted odds ratio aOR, 2.1; 95% CI, 1.0-4.5), grass (aOR, 2.5; 95% CI, 1.2-5.2), and A alternata (aOR, 2.4; 95% CI, 1.1-5.5) was increased when compared with that seen in teens without parental allergen-specific sensitization. Similarly, a higher than expected risk of paternal matched sensitization with their teen to dog (aOR, 2.7; 95% CI, 1.3-5.9), D farinae (aOR, 2.7; 95% CI, 1.4-5.1), and grass (aOR, 2.7; 95% CI, 1.5-5.9) was observed. Conclusion Parental allergen-specific IgE increases the likelihood of sensitization to the same allergen in young adult offspring.
The EDELWEISS collaboration has performed a search for dark matter particles with masses below the GeV-scale with a 33.4-g germanium cryogenic detector operated in a surface lab. The energy deposits ...were measured using a neutron-transmutation-doped Ge thermal sensor with a 17.7~eV (RMS) baseline heat energy resolution leading to a 60~eV analysis energy threshold. Despite a moderate lead shielding and the high-background environment, the first sub-GeV spin-independent dark matter limit based on a germanium target has been achieved. The experiment provides the most stringent, nuclear recoil based, above-ground limit on spin-independent interactions above 600~MeV/c\(^{2}\). The experiment also provides the most stringent limits on spin-dependent interactions with protons and neutrons below 1.3~GeV/c\(^{2}\). Furthermore, the dark matter search results were studied in the context of Strongly Interacting Massive Particles, taking into account Earth-shielding effects, for which new regions of the available parameter space have been excluded. Finally, the dark matter search has also been extended to interactions via the Migdal effect, resulting for the first time in the exclusion of particles with masses between 45 and 150~MeV/c\(^{2}\) with spin-independent cross sections ranging from \(10^{-29}\) to \(10^{-26}\)~cm\(^2\).
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