First Dark Matter Results from the XENON100 Experiment

TL;DR

The XENON100 experiment's initial results set new limits on dark matter WIMP interactions, excluding certain cross-sections and challenging interpretations of other experimental signals.

Contribution

First dark matter search results from XENON100 using 11.17 live days of data, providing the most stringent limits at the time.

Findings

No WIMP candidate events observed in the signal region.

Excluded spin-independent WIMP-nucleon cross-sections above 3.4 x 10^-44 cm^2 for 55 GeV/c^2 WIMPs.

Constraints challenge interpretations of CoGeNT and DAMA signals as light WIMPs.

Abstract

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter WIMPs scattering off 62 kg of liquid xenon in an ultra-low background dual-phase time projection chamber. In this letter, we present first dark matter results from the analysis of 11.17 live days of non-blind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the pre-defined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross-sections above 3.4 x 10^-44 cm^2 for 55 GeV/c^2 WIMPs at 90% confidence level. Below 20 GeV/c^2, this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.