Results on low mass WIMPs using an upgraded CRESST-II detector

Authors: G. Angloher, A. Bento, C. Bucci, L. Canonica, A. Erb, F. v. Feilitzsch, N.Ferreiro Iachellini, P. Gorla, A. Gutlein, P. Huff, J. Jochum, M. Kiefer, C. Kister, H. Kluck, J.C. Lanfranchi, J. Loebell, A. Munster, F. Petricca, W. Potzel, F.
Category: Reviewed Paper

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 $\alpha $ -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.