First results of the EDELWEISS-II WIMP search using Ge cryogenic detectors with interleaved electrodes

Understand

The EDELWEISS-II collaboration has performed a direct search for WIMP dark matter with an array of ten 400 g heat-and-ionization cryogenic detectors equipped with interleaved electrodes for the rejection of near-surface events.

• Six months of continuous operation at the Laboratoire Souterrain de Modane have been achieved.
• The observation of one nuclear recoil candidate above 20 keV in an effective exposure of 144 kgd is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons.
• A cross-section of 1.0x10^-7 pb is excluded at 90%CL for a WIMP mass of 80 GeV/c2.