Cold Dark Matter Searches and the Xenon100 experiment

Laura Baudis (Universität Zürich)

The XENON experiment aims to detect weakly interacting massive particles (WIMPs) via their elastic scattering onXenuclei, using a low background, two-phase time projection chamber. With 1-ton of ultra pure liquid xenon as target, an energy threshold below 10 keVand a background rejection power above 99.5%,XENON could reach a sensitivity close to 10-46cm2 for spin-independent WIMP-nucleon cross sections. To verify the XENON approach to dark matter detection, a first prototype (XENON10) was developed and operated for a period of several months at the GranSassoUnderground Laboratory (LNGS) in Italy. XENON10 data have resulted in a 90% C.L. upper limit of 8.8 x 10-44cm2 for a 100 GeVWIMP. XENON100, a new detector with 170 kg total liquid Xemass, is currently under commissioning at LNGS; the goal is to start the science run in fall 2008. The status and WIMP sensitivity expectations for the new experiment will be presented.