CDMS: World Best Sensitivity to WIMPs

CDMS experiment attempts to observe the signature of Weakly Interacting Massive Particles (WIMP) particle through their elastic scattering with target detectors with very low detection threshold. Events with recoil energies of a few tens of keV and rates <1 event/kg-day are expected. The low energy deposition and rate require all WIMP search experiments to be underground to protect them from cosmic rays. The CDMS II experiment operating in Soudan mines is designed to detect atomic nuclei that have been scattered by incident WIMPs in germanium (Ge) and silicon (Si) crystals. CDMS has the most sensitive exclusion limit on the WIMP neutralino dark matter cross section with ordinary matter, at 10-43 cm2. The current run of CDMS operating in the Soudan mines aims to achieve sensitivity an order of magnitude better than this by end of next year. The next upgrade of CDMS, named SuperCDMS, to be operated in a deeper underground site, has a target sensitivity that will be 100 times better, to be achieved within the next 4 years. CDMS and SuperCDMS will continue to maintain their world leading sensitivity for the next few years to come, either discovering the WIMP dark matter or excluding a large part of the SUSY parameter space, thus fundamentally changing our ideas of the expected SUSY signature. If LHC manages to first observe the signature of supersymmetry by discovering the superparticle, CDMS will still be playing a major role in proving if the discovered particle is indeed the dark matter of the universe. Due to the nature of observation at collliders, it is impossible for LHC to know if the observed particle is long lived or not. Direct search experiments, such as CDMS can verify the nature of the observed particle.

CDMS has demonstrated technology for discriminating WIMPs from cosmogenic and radioactive backgrounds and has a host of potential improvements in the pipeline which will help CDMS maintain its leadership role by extending the sensitivity by a factor of 10 in Soudan and a factor of 100 as part of the SuperCDMS 25kg Phase A.