[en] The CRESST-III experiment, located in the Gran Sasso underground laboratory (LNGS, Italy), aims at the direct detection of dark matter (DM) particles. Scintillating CaWO₄ crystals operated as cryogenic detectors are used as target material for DM-nucleus scattering. The simultaneous measurement of the phonon signal from the CaWO₄ crystal and of the emitted scintillation light in a separate cryogenic light detector is used to discriminate backgrounds from a possible dark matter signal. The experiment aims to significantly improve the sensitivity for low-mass (≲ 5-10 GeV/c²) DM particles by using optimized detector modules with a nuclear recoil-energy threshold ≲ 100 eV. The current status of the experiment as well as projections of the sensitivity for spin-independent DM-nucleon scattering will be presented. (paper)

[en] We analyzed low-background data from the CRESST-II experiment with a total net exposure of 730 kg days to extract limits on double electron capture processes. We established new limits for ⁴⁰Ca with $T_{1/2}^{2\mathrm{\nu <!--\; ??\; -->}2\mathrm{K}}><!--\; >\; -->9.9\times <!--\; ??\; -->{10}^{21}$ y and $T_{1/2}^{0\mathrm{\nu <!--\; ??\; -->}2\mathrm{E}\mathrm{C}}><!--\; >\; -->1.4\times <!--\; ??\; -->{10}^{22}$ y and for ¹⁸⁰W with $T_{1/2}^{2\mathrm{\nu <!--\; ??\; -->}2\mathrm{K}}><!--\; >\; -->3.1\times <!--\; ??\; -->{10}^{19}$ y and $T_{1/2}^{0\mathrm{\nu <!--\; ??\; -->}2\mathrm{E}\mathrm{C}}><!--\; >\; -->9.4\times <!--\; ??\; -->{10}^{18}$ y at 90% CL. Depending on the process, these values improve the currently best limits by a factor of $\sim <!--\; ???\; -->1.4\text{--}30$. (paper)

[en] Understanding the nature and origin of dark matter is one of the most important challenges for modern particle physics. During the previous decade the sensitivities of direct dark matter searches have improved by several orders of magnitude. These experiments focus their work mainly on the search for dark-matter particles interacting with nuclei (e.g. Weakly Interacting Massive Particles, WIMPs). However, there exists a large variety of different candidates for dark-matter particles. One of these candidates, the so-called dark photon, is a long-lived vector boson with a kinetic mixing to the standard-model photon. In this work we present the preliminary results of our search for dark photons. Using data from the direct dark matter search CRESST-II Phase 2 we can improve the existing constraints for the kinetic mixing for dark-photon masses between 0.3 and 0.5 keV/c². In addition, we also present projected sensitivities for the next phases of the CRESST-III experiment showing great potential to improve the sensitivity for dark-photon masses below 1 keV. (paper)

[en] The large statistics collected during the operation of a ZnMoO₄ array, for a total exposure of 1.3 kg day of ¹⁰⁰Mo, allowed the first bolometric observation of the two neutrino double beta decay of ¹⁰⁰Mo. The observed spectrum of each crystal was reconstructed taking into account the different background contributions due to environmental radioactivity and internal contamination. The analysis of coincidences between the crystals allowed the assignment of constraints to the intensity of the different background sources, resulting in a reconstruction of the measured spectrum down to an energy of ∼300 keV. The half-life extracted from the data is T_1/2^2ν = [7.15 ± 0.37 (stat) ± 0.66 (syst)] × 10¹⁸ y. (paper)