Silicon Detector Dark Matter Results from the Final Exposure of CDMS II

• Main Authors: Anderson, Adam Jonathan (Contributor), Billard, Julien (Contributor), Figueroa-Feliciano, Enectali (Contributor), Hertel, Scott Alexander (Contributor), Leman, Steven W. (Contributor), McCarthy, Kevin Ahmad (Contributor)
• Other Authors: Lincoln Laboratory (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-03-03T15:50:21Z.
• Subjects: Article
• Online Access: Get fulltext

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[+0.20 over −0.08](stat)[+0.28 over −0.24](syst). Other known backgrounds from neutrons and [superscript 206]Pb 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/c[superscript 2]. 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/c[superscript 2] and WIMP-nucleon cross section of 1.9 × 10[superscript −41]  cm[superscript 2].
National Science Foundation (U.S.) (Grant AST-9978911)
National Science Foundation (U.S.) (Grant NSF-0847342)
National Science Foundation (U.S.) (Grant NSF-1151869)
National Science Foundation (U.S.) (Grant PHY-0542066)
National Science Foundation (U.S.) (Grant PHY-0503729)
National Science Foundation (U.S.) (Grant PHY-0503629)
National Science Foundation (U.S.) (Grant PHY-0503641)
National Science Foundation (U.S.) (Grant PHY-0504224)
National Science Foundation (U.S.) (Grant PHY-0705052)
National Science Foundation (U.S.) (Grant PHY-0801708)
National Science Foundation (U.S.) (Grant PHY-0801712)
National Science Foundation (U.S.) (Grant PHY-0802575)
National Science Foundation (U.S.) (Grant PHY-0847342)
National Science Foundation (U.S.) (Grant PHY-0855299)
National Science Foundation (U.S.) (Grant PHY-0855525)
National Science Foundation (U.S.) (Grant PHY-1102795)
National Science Foundation (U.S.) (Grant PHY-1205898)
United States. Dept. of Energy (Contract DE-AC03-76SF00098)
United States. Dept. of Energy (Contract DE-FG02-92ER40701)
United States. Dept. of Energy (Contract DE-FG02-94ER40823)
United States. Dept. of Energy (Contract DE-FG03-90ER40569)
United States. Dept. of Energy (Contract DE-FG03-91ER40618)
United States. Dept. of Energy (Contract DE-SC0004022)