Results from 730 kg days of the CRESST-II Dark Matter search

By G. Angloher, M. Bauer, I. Bavykina, A. Bento, C. Bucci, C. Ciemniak, G. Deuter, F. Feilitzsch, D. Hauff, P. Huff and 26 more. 2011

750 citations recorded by the source corpus.

The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds.Sixty-seven events are found in the acceptance region where a WIMP signal in the form of low energy nuclear recoils would be expected. We estimate background contributions to this observation from four sources: (1) “leakage” from the e/γ-band (2) “leakage” from the α-particle band (3) neutrons and (4) 206Pb recoils from 210Po decay. Using a maximum likelihood analysis, we find, at a statistical significance of more than 4σ, that these sources alone are not sufficient to explain the data. The addition of a signal due to scattering of relatively light WIMPs could account for this discrepancy, and we determine the associated WIMP parameters.

Subfields: Electrical and Electronic Engineering, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/5addad278d33d7b2c9fc089afd29bf805b3d913c

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Citations in the corpus

Galactic Searches for Dark Matter (2012, methodology): “Laboratory, using a scintillating material of Calcium Tungstate (CaWO 4). CRESST-II uses a combination of phonon and scintillation light to reduce backgrounds, and now has an exposure of 730 kg-days (Angloher et al., 2012). It has observed 67 events in its acceptance nuclear recoil energy range of 1”
HIGH-RESOLUTION MASS MODELS OF DWARF GALAXIES FROM LITTLE THINGS (2015, background): “The cosmological importance of DM has driven efforts to explore the physical nature of DM particles and to attempt their direct detection (Moore et al. 2001; Gaitskell 2004; Angloher et al. 2012; Akerib et al. 2014, and references therein).”
Dark matter direct-detection experiments (2015, background): “m 10.2keV nr to 19.0keV nr. An excess of events is observed, corresponding to a WIMP mass of 11.6GeV/c2 (4.2˙) or 25.3GeV/c2 (4.7˙) with a cross-section of 3.7 210 41 cm or 1.6 10 42 cm2, respectively[205]. It is worth mentioning that the main background in this analysis is due to collisions of lead”
Characterising dark matter searches at colliders and direct detection experiments: vector mediators (2014, positive): “It is also an interesting region both from a theoretical perspective, since mDM ' 5 GeV is predicted in many models of asymmetric DM (see [103] for a recent review), and from a phenomenological perspective, since it is the region where CoGeNT [104–107], CRESSTII [108], CDMS-Si [109] and DAMA/LIBRA [”
Constrained supersymmetry after two years of LHC data: a global view with Fittino (2012, result): “While some of the collaborations, DAMA/LIBRA [107], CoGeNT [41, 108] and CRESST [109], promulgate the detection of a signal, others, primarily XENON100 [39], have shown upper limits nominally excluding the regions of signal detection.”
micrOMEGAs4.1: Two dark matter candidates (2014, background): “At the same time several anomalies have been observed in both direct detection [4, 5, 6, 7, 8] and indirect detection experiments [9, 10, 11, 12].”