There is strong cosmological and astrophysical evidence that more than 85% of the matter in the Universe is composed of non-luminous --dark-- matter, which is fundamentally different from ordinary matter. Of the many candidate particles, Weakly Interacting Massive Particles (WIMPs), arising in extensions to the Standard Model, are particularly well-motivated. One method to detect WIMPs is to measure the nuclear recoils produced in their rare elastic collisions with ordinary matter. The predicted interaction rates are extraordinarily low: less than one event-per-ton-per-yr and required very sensitive detectors made of ultra-low radioactivity materials. Experiments based on liquid xenon, with a combination of a large target mass and excellent background rejection, offer the potential to meet this sensitivity goal.
I will introduce the dark matter problem and explore dark matter candidates and their detection methods. I will then discuss the status of current direct detection dark matter experiments. My group plays a leading role in the XENON dark matter collaboration and I will conclude with presenting the recent results from the world's most sensitive dark matter detector, the xenon-based XENON1T experiment.