Abstract
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 \unit[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 \unit[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.
Highlights
Several experiments, DAMA [1], CoGeNT [2], CRESSTII [3] and CDMS II Si [4] reported observation of an excess of events at low energies above their background estimates
A detailed description of the CRESST-II set-up, data acquisition (DAQ), readout, and the procedures for controlling detector stability, as well as reconstructing the deposited energy from the measured pulses can be found in earlier publications [8,9]
These artificial pulses are created by superimposing signal templates, obtained by averaging a large number of pulses from the 122 keV 57Co calibration peak, on empty baselines periodically sampled throughout the run
Summary
DAMA [1], CoGeNT [2], CRESSTII [3] and CDMS II Si [4] reported observation of an excess of events at low energies above their background estimates. This could be attributed to scattering of light WIMPs with a mass in the 6 to 30 GeV/c2 range, while other experiments like XENON100 [5], LUX [6] and SuperCDMS [7] exclude this region of parameter space. Non-blinded 29.35 kg live days of data of a single detector module from this first period will be used to derive the low-mass WIMP limit presented in this letter
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
