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CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3–4 GeV/\\[c^2\\]) are presented.

Models for light dark matter particles with masses below 1 GeV/c [Formula omitted] are a natural and well-motivated alternative to so-far unobserved weakly interacting massive particles. Gram-scale cryogenic calorimeters provide the required detector performance to detect these particles and extend the direct dark matter search program of CRESST. A prototype 0.5 g sapphire detector developed for the [Formula omitted]-cleus experiment has achieved an energy threshold of [Formula omitted] eV. This is one order of magnitude lower than for previous devices and independent of the type of particle interaction. The result presented here is obtained in a setup above ground without significant shielding against ambient and cosmogenic radiation. Although operated in a high-background environment, the detector probes a new range of light-mass dark matter particles previously not accessible by direct searches. We report the first limit on the spin-independent dark matter particle-nucleon cross section for masses between 140 and 500 MeV/c [Formula omitted].

The CRESST-II cryogenic dark matter search aims for the detection of WIMPs via elastic scattering off nuclei in CaWO 4 crystals. We present results from a low-threshold analysis of a single upgraded detector module. This module efficiently vetoes low energy backgrounds induced by α -decays on inner surfaces of the detector. With an exposure of 29.35 kg live days collected in 2013 we set a limit on spin-independent WIMP-nucleon scattering which probes a new region of parameter space for WIMP masses below 3 GeV/c 2 , previously not covered in direct detection searches. A possible excess over background discussed for the previous CRESST-II phase 1 (from 2009 to 2011) is not confirmed.

The experimental detection of the CE ν NS allows the investigation of neutrinos and neutrino sources with all-flavor sensitivity. Given its large content in neutrons and stability, Pb is a very appealing choice as target element. The presence of the radioisotope 210 Pb (T 1 / 2 ∼ 22 yrs) makes natural Pb unsuitable for low-background, low-energy event searches. This limitation can be overcome employing Pb of archaeological origin, where several half-lives of 210 Pb have gone by. We present results of a cryogenic measurement of a 15 g PbWO 4 crystal, grown with archaeological Pb (older than ∼ 2000 yrs) that achieved a sub-keV nuclear recoil detection threshold. A ton-scale experiment employing such material, with a detection threshold for nuclear recoils of just 1 keV would probe the entire Milky Way for SuperNovae, with equal sensitivity for all neutrino flavors, allowing the study of the core of such exceptional events.

In this work, we want to highlight the potential of lithium as a target for spin-dependent dark matter search in cryogenic experiments, with a special focus on the low-mass region of the parameter space. We operated a prototype detector module based on a \\[\\hbox {Li}_2\\hbox {MoO}_4\\] target crystal in an above-ground laboratory. Despite the high background environment, the detector sets a competitive limit on spin-dependent interactions of dark matter particles with protons and neutrons for masses between \\[0.8~\\hbox {GeV/c}^2\\] and \\[1.5~\\hbox {GeV/c}^2\\].

Despite the multiple and convincing evidence of the existence of dark matter (DM) in our Universe, its detection is one of the most pressing questions in particle physics. As of today, there is no unambiguous hint which could clarify the particle nature of DM. For these reasons, a huge experimental effort is ongoing, trying to realize experiments which can probe the particle properties of DM. In particular, direct search experiments are trying to cover the largest possible mass range, from a few MeVs up to TeVs. Particularly suited for the sub-GeV mass region are detectors containing light nuclei, which are sensitive to the scattering of light DM candidates. Among them, we investigate a carbon-based absorber to explore DM masses down to the MeV region. Thanks to their cryogenic properties (high Debye temperature and long-lived phonon modes), carbon-based materials operated as low temperature calorimeters could reach an energy threshold in the eV range and would allow for the exploration of new parameters of the DM–nucleus cross section. Despite several proposals, the possibility of operating a carbon-based cryogenic detector is yet to be demonstrated. In this contribution, the preliminary results obtained with a diamond absorber operated with a TES temperature sensor will be reported. The potential of such a detector in the current landscape of DM searches will also be illustrated.

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in \\[\\mathrm {CaWO_4}\\] crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to \\[(68 \\pm 16)\\,\\mathrm {\\%}\\] of the electromagnetic background in the energy range between 1 and \\[40\\,\\mathrm {keV}\\].

To cope with the foreseen demand for tungsten-based TESs in the current and future phases of the CRESST experiment, we investigated the possibility to implement a reliable, simple and reproducible fabrication method using sputtering. In this contribution, we present the method under development for tungsten deposition using conventional magnetron sputtering with xenon as sputtering gas. TESs with transition temperatures ( T c ) down to 15 mK have been obtained with transition widths smaller than 1 mK. We also give a first assessment on the reproducibility of the process and present the potential for tuning of the T c .

RES-NOVA is a newly proposed experiment for detecting neutrinos from astrophysical sources, mainly Supernovae, using an array of cryogenic detectors made of PbWO4 crystals produced from archaeological Pb. This unconventional material, characterized by intrinsic high radiopurity, enables low-background levels in the region of interest for the neutrino detection via Coherent Elastic neutrino-Nucleus Scattering (CEνNS). This signal lies at the detector energy threshold, O(1 keV), and it is expected to be hidden by naturally occurring radioactive contaminants of the crystal absorber. Here, we present the results of a radiopurity assay on a 0.84 kg PbWO4 crystal produced from archaeological Pb operated as a cryogenic detector. The crystal internal radioactive contaminations are: 232Th <40 μBq/kg, 238U <30 μBq/kg, 226Ra 1.3 mBq/kg and 210Pb 22.5 mBq/kg. We also present a background projection for the final experiment and possible mitigation strategies for further background suppression. The achieved results demonstrate the feasibility of realizing this new class of detectors.

Identifying the nature and origin of dark matter is one of the major challenges for modern astro and particle physics. Direct dark-matter searches aim at an observation of dark-matter particles interacting within detectors. The focus of several such searches is on interactions with nuclei as provided e.g. by weakly interacting massive particles. However, there is a variety of dark-matter candidates favoring interactions with electrons rather than with nuclei. One example are dark photons, i.e., long-lived vector particles with a kinetic mixing to standard-model photons. In this work we present constraints on this kinetic mixing based on data from CRESST-II Phase 2 corresponding to an exposure before cuts of 52 kg-days. These constraints improve the existing ones for dark-photon masses between 0.3 and 0.7 keV/c 2 .