Extending the search capabilities of liquid xenon dark matter experiments

A promising solution to the dark matter problem is the Weakly Interacting Massive Particle (WIMP), a proposed beyond-the-standard-model particle that would permeate the galaxy and interact extremely weakly with baryonic matter. WIMPs in the vicinity of Earth would produce rare low energy (1's - 10's of keV) nuclear recoils that could be observed in a low-background detector. Currently, several of the leading experiments searching for WIMP interactions use liquid xenon as a scattering target. These experiments measure both scintillation light and ionization to reconstruct the energy, position, and particle type of the interaction to discriminate signal from background. In this talk, I will describe the search for dark matter with the LUX experiment, a dual-phase xenon TPC operated underground in Lead, South Dakota. I will then discuss how a deeper understanding of charge production and scintillation emission in liquid xenon can allow experiments like LUX to explore new parameter space. To this end, we have made several measurements to calibrate the scintillation and ionization response of liquid xenon to nuclear recoils. I will describe these measurements and show how they allow LUX and other liquid xenon experiments to robustly extend their search windows to either constrain or discover a wider array of WIMP dark matter models.