We have found no hints of dark matter in a first thorough and blind search for dark matter with XENON100:
Every part that goes into the construction of our detectors has to be specially selected to be extremely cleam in terms of radioactive impurities. This effort is published:
We have improved the approach to the search for dark matter in direct search experiments using a profile likelihood approach that allows a natural transition from a limit to a discovery:
We have published our excellent understanding of the background in the XENON100 detector that comes from beta and gamma radiation:
E. Aprile et al. (XENON100), Study of the electromagnetic background in the XENON100 experiment, arXiv:1101.3866. The paper is also published in Physical Review D83 (2011), 082001, with an erratum ibid. D85 (2012), 029904.
Already the XENON100 commissioning run is sensitive enough to provide relevant limits on dark matter interactions. We have published these first results: