Experimental HEP Seminar

The XENON Dark Matter Search

Elena Aprile

Columbia University

The goal of the XENON experiment is to detect weakly interacting massive particles (WIMPs) via their elastic scattering on xenon nuclei, using a very sensitive, low background, two-phase time projection chamber. WIMPs are the most popular candidates for dark matter and Supersymmetry naturally provides an ideal WIMP in its lightest particle, the neutralino. Predicted rates are as low as 1 event/100 kg/day, demanding massive detectors with powerful background rejection capabilities. Using 1-ton of ultra pure liquid xenon, an energy threshold less than 10 keV and a rejection power better than 99.5% the XENON sensitivity reach is 10^-46 cm² for spin-independent WIMP-nucleon cross section. The performance of a first prototype (XENON10), still in operation underground at the Gran Sasso National Laboratory, has validated the XENON approach to dark matter direct detection. A blind analysis of 60 live days of XENON10 data, collected between October 2006 and February 2007, has led to a 90% C.L. upper limit of 8.8 x 10^-44 cm² for a 100 GeV WIMP, making XENON the most sensitive dark matter experiment operating today, worldwide. I will discuss the results and the status of the next phase (XENON100) which should lead to a significant sensitivity improvement within 2008 and pave the way for the 1-ton experiment.