LUX-ZEPLIN

Abstract:

It has been proven by several astronomical observations that dark matter exists, but no particle candidates have been observed yet. The CRESST experiment aims to directly detect dark matter particles elastically scattering off nuclei in CaWO4 crystals which are operated at mK temperatures. With nuclear recoil energy thresholds as low as 0.3 keV [2] and 0.6 keV [3], for the detector modules LISE and TUM40, respectively, CRESST is ideally suited for the detection of low-mass dark matter particles [5]. Additionally, the radiopurity of the crystals is another important factor for the detector performance. For a detailed understanding of the detector backgrounds, we simulate the radioactive contaminations of the TUM40 detector module with Geant4. The outcome of this simulation will be vital for the CRESST-III experiment. In this contribution, we discuss our results of the search for dark matter and dark photons achieved with the detector module Lise of CRESST-II. We will discuss the status of CRESST-III Phase 1 which started taking data in 2016.

Abstract:

CRESST is a multi-stage experiment directly searching for dark matter (DM) using cryogenic CaWO4 crystals. Previous stages established leading limits for the spin-independent DM-nucleon cross section down to DM-particle masses mDM below 1GeV/c2. Furthermore, CRESST performed a dedicated search for dark photons (DP) which excludes new parameter space between DP masses mDP of 300 eV/c2 to 700 eV/c2. In this contribution we will discuss the latest results based on the previous CRESST-II phase 2 and we will report on the status of the current CRESST-III phase 1: in this stage we have been operating 10 upgraded detectors with 24, g target mass each and enhanced detector performance since summer 2016. The improved detector design in terms of background suppression and reduction of the detection threshold will be discussed with respect to the previous stage. We will conclude with an outlook on the potential of the next stage, CRESST-III phase 2.

Abstract:

These proceedings address a recent publication by the ANITA collaboration of four upward-pointing cosmic-ray-like events observed in the first flight of ANITA. Three of these events were consistent with stratospheric cosmic-ray air showers where the axis of propagation does not intersect the surface of the Earth. The fourth event was consistent with a primary particle that emerges from the surface of the ice suggesting a possible τ-lepton decay as the origin of this event. These proceedings follow-up on the modeling and testing of the hypothesis that this event was of τ neutrino origin.