We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a twophase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8±0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0×10-45 cm2 for a WIMP mass of 50 GeV/c2 at 90% confidence level. (13) We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows to select only the innermost 48 kg as ultra-low background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in a pre-defined signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic WIMP-nucleon scattering cross-sections above 7.0 × 10 −45 cm 2 for a WIMP mass of 50 GeV/c 2 at 90% confidence level.

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below 10 GeV/c2. This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9 GeV/c2 and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.

We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10  GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6  GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41)  cm2.

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We report results from a blind analysis of the final data taken with the Cryogenic Dark Matter Search experiment (CDMS II) at the Soudan Underground Laboratory, Minnesota, USA. A total raw exposure of 612 kg-days was analyzed for this work. We observed two events in the signal region; based on our background estimate, the probability of observing two or more background events is 23%. These data set an upper limit on the Weakly Interacting Massive Particle (WIMP)-nucleon elastic-scattering spin-independent cross-section of 7.0 × 10 −44 cm 2 for a WIMP of mass 70 GeV/c 2 at the 90% confidence level. Combining this result with all previous CDMS II data gives an upper limit on the WIMP-nucleon spin-independent cross-section of 3.8 × 10 −44 cm 2 for a WIMP of mass 70 GeV/c 2 . We also exclude new parameter space in recently proposed inelastic dark matter models. Cosmological observations [1] have led to a concordance model of the universe where ∼85% of matter is non-baryonic, non-luminous and non-relativistic at the time of structure formation. Weakly Interacting Massive Particles (WIMPs) [2] are a class of candidates for this dark matter which are particularly well motivated by proposed extensions to the Standard Model of particle physics and by thermal production models for dark matter in the early universe [3,4,5,6]. WIMPs, distributed in a halo surrounding our galaxy, would coherently scatter off nuclei in terrestrial detectors [7,8,9] with a mean recoil energy of ∼ tens of keV, presently limited by observation to a rate of less than 0.1 event 5,6,10]. Direct search experiments seek recoil signatures of these interactions and have achieved the sensitivity to begin testing the most interesting classes of WIMP models [11,12,13,14].The Cryogenic Dark Matter Search (CDMS II) experiment, located at the Soudan Underground Laboratory, uses 19 Ge (∼230 g) and 11 Si (∼100 g) particle detectors operated at cryogenic temperatures (< 50 mK) [11,15]. Each detector is a disk ∼10 mm thick and 76 mm in diameter. Particle interactions in the detectors deposit energy in the form of phonons and ionization. Phonon sensors on the top of each detector are connected to four phonon readout channels to allow measurement of the recoil enarXiv:0912.3592v1 [astro-ph.CO]