Principal Investigator
Prof. Rick Gaitskell

(May 12, 2004) CDMS II in the News

(May 3, 2004) CDMS II Announces new results

The CDMS II (Cryogenic Dark Matter Search) experiment is announcing today its latest results at the APS meeting in Denver.

The sensitivity of the CDMS II experiment is now a factor of 4 better than any other dark matter direct detection experiment worldwide. We see NO events consistent with WIMP interactions in spite of operating for some 53 live days of operation. These new results provide significant new constraints on candidate SUSY (Supersymmetry) models for particle dark matter, and are strongly incompatible with the existing DAMA annual modulation signal. Selected plots from the paper are shown below. Full details are available in the PRL preprint.

PDF of paper from this server, or from arxiv.org preprint server version of CDMS II PRL submission (available May 4, 2004)

Press Release, Mark Nikel, Brown Press Office

New limit on the WIMP-nucleon scalar cross section from CDMS~II at Soudan with no candidate events in 19.4 kg-d effective Ge exposure (solid curve). Parameter space above the curve is excluded at the 90% C.L.These limits are inconsistent with the DAMA (1-4) 3\sigma signal region (closed contour) if it is due to scalar coherent WIMP interactions. These limits constrain supersymmetry models, for example{Baltz01} (dark grey) and {Bottino03} (light grey). Also shown are limits from CDMS at SUF~\cite{akerib03} (dots), EDELWEISS~\cite{edel0203} ($\times$'s), and the second, non-blind analysis of CDMS~II at Soudan with 1 nuclear-recoil candidate event (dashes). All curves{http://dmtools.brown.edu}are normalized following {lewin}, using the Helm spin-independent form-factor, $A^2$ scaling, WIMP characteristic velocity v0 = 220 km/s, mean Earth velocity vE = 232 km/s, and rho = 0.3 GeV/cm^3.

Ionization yield versus recoil energy for calibration data with a 252Cf gamma and neutron source for detectors Z2, Z3 and Z5 in Tower 1 showing the $\pm 2 \sigma$ gamma band (solid curves) and the $\pm 2 \sigma$ nuclear-recoil band (dashed curves) for Z5, the detector with the worst noise of these three.Events with ionization yield $ < 0.75$ (grey) are shown only if they pass the phonon-timing cuts. The vertical line is the 10~keV analysisthreshold for these three detectors.

Posters of CDMS and Brown Group Research

[click thumbnails for pdf]

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CDMS II - Cryogenic Dark Matter Search, phase II