Michael Willers

Search for low-mass Dark Matter with the CRESST experiment

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) 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 the emitted scintillation light in a separate cryogenic light detector is used to discriminate backgrounds from a possible dark matter signal. Since cryogenic detectors are very sensitive to small energy deposits induced, e.g., by the interactions of light DM particles, the experiment is able probe the low-mass region of the parameter space for spin-independent DM-nucleus scattering with high sensitivity.

Recent results from the CRESST-II experiment — obtained using a 300 g detector with a nuclear recoil energy threshold of 307 eV — provide the world best limit for masses below 1.7 GeV/c^2. The CRESST-III experiment aims to significantly improve the sensitivity for low-mass DM particles by using dedicated detector modules. Each such module consists of a ~24 g CaWO4 target crystal and a 20x20 mm^2 Silicon-on-Sapphire light detector and will allow to reach a nuclear recoil energy threshold of ~100 eV.

Phase 1 of the CRESST-III experiment, where 10 detector modules with a total target mass of 240 g will be operated, recently started it's commissioning phase and data taking is expected to start in the summer of 2016. In this talk I will present the most recent results from the CRESST-II experiment as well as the status and future perspectives of the CRESST-III experiment.