Improved Measurements of the β-Decay Response of Liquid Xenon with the LUX Detector

Abstract

The LUX experiment was based on a liquid-xenon time-projection chamber that was located on the 4,850' level of the Sanford Underground Research Facility until it was decommissioned in 2016. In total, the LUX detector contained about 370 kg of xenon, 250 kg of which was active. LUX was designed primarily to detect WIMP dark matter, and produced world-leading limits on the WIMP scattering cross section. In this presentation, I report results from an extensive set of measurements of the β-decay response in liquid xenon. These measurements are derived from high-statistics calibration data from injected sources of both tritium and carbon-14 in the LUX detector after the WIMP-search runs had been completed. The mean light-to-charge ratio is reported for 13 electric field values ranging from 43 to 491 V/cm, and for energies ranging from 1.5 to 145 keV.