UC Santa Barbara

There is abundant astrophysical evidence for the existence of dark matter, and a growing body of evidence for what it is not, but we know little about what it is. Weakly Interacting Massive Particles (WIMPs) are a theoretical class of particles which is a leading candidate for the composition of dark matter. The LUX-ZEPLIN experiment, a large dual-phase xenon time projection chamber, was designed to search for WIMPS and has set world-leading exclusion limits on WIMP - nucleus cross sections. Performing such a search requires detailed modeling and precise calibration of backgrounds so that they are not confused for a signal from a WIMP. Certain classes of backgrounds, such as those involving a vacancy in an atom's inner electron shell, are particularly tricky to model and calibrate. Here I describe LZ's WIMP search, how its xenon skin can enable the calibration of these backgrounds, and the insights this provides into other experimental backgrounds.