This paper reports on the development of a technology involving 100 Mo-enriched scintillating bolometers, compatible with the goals of CUPID, a proposed nextgeneration bolometric experiment to search for neutrinoless double-beta decay. Large mass (∼ 1 kg), high optical quality, radiopure 100 Mo-containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the doublebeta transition of 100 Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α-induced dominant background above 2.6 MeV is better than 8σ . Less than 10 µBq/kg activity of 232 Th ( 228 Th) and 226 Ra in the crystals is ensured by boule recrystallization. The potential of 100 Mo-enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg×d exposure: the two neutrino double-beta decay half-life of 100 Mo has been measured with the up-to-date highest accuracy as T 1/2 = [6.90 ± 0.15(stat.) ± 0.37(syst.)] × 10 18 years. Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of 100 Mo.
they elastically scatter off nuclei [4,5]. In recent decades, significant advances have been made in the search for WIMPs in the GeV/c 2 -to TeV/c 2 -range that is natural for Supersymmetry [6][7][8]. However, in the light of the absence of signal in that region there is an increasing interest in DM particles in the GeV/c 2 and sub-GeV/c 2 mass range [9][10][11][12][13][14][15]. These searches require experimental thresholds as low as a few tens of eV, a performance that can be attained by cryogenic detectors [16,17]. A particular advantage of such detector technology is that the thermal signal is not affected by the strong quenching effects that tend to severely reduce the amplitude of ionization or scintillation signals at low energy. This paper describes the results obtained by the EDELWEISS collaboration with a 33.4-g Ge detector demonstrating that such a device equipped with a neutron-transmutation-doped Ge (Ge-NTD) sensor [18] can reach the sensitivity to probe the sub-GeV domain. As a proof of the relevance of this technology, it is used in
The p-adic Simpson correspondence, recently initiated by Gerd Faltings, aims at describing all p-adic representations of the fundamental group of a proper smooth variety over a p-adic field in terms of linear algebra—namely Higgs bundles. This book undertakes a systematic development of the theory following two new approaches. It mainly focuses on generalized representations of the fundamental group that are p-adically close to the trivial representation. The first approach relies on a new family of period rings built from the torsor of deformations of the variety over a universal p-adic thickening defined by J. M. Fontaine. The second approach introduces a crystalline-type topos and replaces the notion of Higgs bundles with that of Higgs isocrystals. The book shows the compatibility of the two constructions and the compatibility of the correspondence with the natural cohomologies. The last part of the book contains results of wider interest in p-adic Hodge theory. The reader will find a concise introduction to Faltings' theory of almost étale extensions and a chapter devoted to the Faltings topos. Though this topos is the general framework for Faltings' approach in p-adic Hodge theory, it remains relatively unexplored.
CUPID-Mo is a bolometric experiment to search for neutrinoless double-beta decay (0νβ β ) of 100 Mo. In this article, we detail the CUPID-Mo detector concept, assema e-mail: andrea.giuliani@csnsm.in2p3.fr bly, installation in the underground laboratory in Modane in 2018, and provide results from the first datasets. The demonstrator consists of an array of 20 scintillating bolometers comprised of 100 Mo-enriched 0.2 kg Li 2 MoO 4 crystals. The
The EDELWEISS experiment has improved its sensitivity for the direct search for WIMP dark matter. In the recoil energy range relevant for WIMP masses below 10 TeV/c 2 , no nuclear recoils were observed in the fiducial volume of a heat-and-ionization cryogenic Ge detector operated in the lowbackground environment of the Laboratoire Souterrain de Modane in the Fréjus Tunnel, during an effective exposure of 7.4 kg·d. This result is combined with the previous EDELWEISS data to derive a limit on the crosssection for spin-independent interaction of WIMPs and nucleons as a function of WIMP mass, using standard nuclear physics and astrophysical assumptions. This limit excludes at more than 99.8%CL a WIMP candidate with a mass of 44 GeV/c 2 and a cross-section of 5.4×10 −6 pb, as reported by the DAMA collaboration. A first sample of supersymmetric models are also excluded at 90%CL.
New Experiments With Spheres-Gas (NEWS-G) is a direct dark matter detection experiment using SphericalProportional Counters (SPCs) with light noble gases to search for low-mass Weakly Interacting Massive Particles (WIMPs). We report the results from the first physics run taken at the Laboratoire Souterrain de Modane (LSM) with SEDINE, a 60 cm diameter prototype SPC operated with a mixture of Ne + CH 4 (0.7 %) at 3.1 bars for a total exposure of 9.7 kg · days. New constraints are set on the spin-independent WIMP-nucleon scattering cross-section in the sub-GeV/c 2 mass region. We exclude cross-sections above 4.4 × 10 −37 cm 2 at 90 % confidence level (C.L.) for a 0.5 GeV/c 2 WIMP. The competitive results obtained with SEDINE are promising for the next phase of the NEWS-G experiment: a 140 cm diameter SPC to be installed at SNOLAB by summer 2018.
21 pages, 5 figuresThe 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 gamma-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 less than 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 4.4x10^-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
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