Results from the CDMS II Experiment

TL;DR

The CDMS II experiment at Soudan conducted a blind analysis of data from 30 detectors, finding no WIMP events and setting new upper limits on WIMP-nucleon cross sections, with ongoing data collection for future sensitivity improvements.

Contribution

This paper reports the latest results from the CDMS II experiment, including the first upper limits on WIMP interactions and the transition to the SuperCDMS upgrade.

Findings

Zero WIMP candidate events observed in the analyzed data

Set an upper limit of 6.6 x 10^-44 cm^2 on WIMP-nucleon cross section

Ongoing data collection with upgraded detectors for improved sensitivity

Abstract

I report recent results and the status of the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory in Minnesota, USA. A blind analysis of data taken by 30 detectors between October 2006 and July 2007 found zero events consistent with WIMPs elastically scattering in our Ge detectors. This resulted in an upper limit on the spin-independent, WIMP-nucleon cross section of 6.6 x 10^-44 cm^2 (4.6 x 10^-44 cm^2 when combined with our previous results) at the 90% C.L. for a WIMP of mass 60 GeV/c^2. In March 2009 data taking with CDMS II stopped in order to install the first of 5 SuperTowers of detectors for the SuperCDMS Soudan project. Analysis of data taken between August 2007 and March 2009 is ongoing.