Abstract

The Large Underground Xenon experiment is searching for interactions of galactic dark matter particles in a 250 kg liquid xenon target. LUX features a double-phase xenon Time Projection Chamber at its core, and operates in a low background environment at the 4850-ft level of the Sanford Underground Research Facility, South Dakota, USA . Results from its first science run completed in 2013 put new constraints on the elastic scattering of Weakly Interacting Massive Particles (WIMPs) off nucleons. Very low energy threshold for nuclear recoil detection and novel calibration techniques have allowed a 20-fold improvement in sensitivity for low mass WIM Ps relative to the previous leading experiment, changing the landscape of direct searches for light WIM Ps. The null result from LUX can only be reconciled with controversial signal claims by other experiments under the most contrived set of astrophysical, particle physics and experimental assumptions. I will describe the experiment and this significant result, and discuss future prospects as LUX enters a longer science run in 2014.