Author/Authors :
G. Angloher، نويسنده , , G. and Bucci، نويسنده , , C. and Christ، نويسنده , , P. and Cozzini، نويسنده , , C. and von Feilitzsch، نويسنده , , F. and Hauff، نويسنده , , D. and Henry، نويسنده , , S. and Jagemann، نويسنده , , Th and Jochum، نويسنده , , J. L. Kraus، نويسنده , , H. and Majorovits، نويسنده , , B. and Ninkovic، نويسنده , , J. and Petricca، نويسنده , , F. and Potzel، نويسنده , , W. and Prِbst، نويسنده , , F. and Ramachers، نويسنده , , Y. and Razeti، نويسنده , , M. and Rau، نويسنده , , W. and Seidel، نويسنده , , W. Marshall Stark، نويسنده , , M. and Stodolsky، نويسنده , , L. A. Tolhurst، نويسنده , , A.J.B. and Westphal، نويسنده , , W. and Wulandari، نويسنده , , H.، نويسنده ,
Abstract :
We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used. Data from early 2004 with two 300 g CRESST-II prototype detector modules are presented, with a net exposure of 20.5 kg days. The modules consist of a CaWO4 scintillating “target” crystal and a smaller cryogenic light detector. The combination of phonon and light signals leads to a strong suppression of non-nuclear recoil backgrounds. Using this information to define an acceptance region for nuclear recoils we have 16 events from the two modules, corresponding to a rate for nuclear recoils between 12 and 40 keV of (0.87 ± 0.22) events/(kg day). This is compatible with the rate expected from neutron background, and most of these events lie in the region of the phonon-light plane anticipated for neutron-induced recoils. A particularly strong limit for WIMPs with coherent scattering results from selecting a region of the phonon-light plane corresponding to tungsten recoils, where the best module shows zero events.
Keywords :
WIMPs , Dark matter , low temperature detectors , CaWO4 , Background discrimination
