University of Pennsylvania Physics & Astronomy Colloquium

The existence of dark matter is strongly supported by an abundance of astrophysical and cosmological evidence, but has yet to be directly detected. Liquid Xe detectors have been a game changer in the field of dark matter detection, bringing about astonishing improvements in sensitivity over the past decade. The LUX-ZEPLIN (LZ) experiment is a multi-tonne dark matter direct detection experiment operating 4850 feet underground at the Sanford Underground Research Facility in Lead, South Dakota. The experiment utilizes a liquid xenon time projection chamber (TPC) with an active mass of 7 tonnes that will search for the low energy signatures from interactions with Weakly Interacting Massive Particle (WIMP) dark matter in our galactic halo and other rare physics processes. LZ published in 2023 its first WIMP search results with an exposure of 60 live days using a fiducial mass of 5.5 tonnes. These results set world-leading limits on spin-independent WIMP-nucleon cross-sections for masses above 9 GeV/c^2. In this talk, I will discuss the evidence for dark matter and present the dark matter search results from the first science run of LZ, report on the experiment's status and discuss the next steps towards a global xenon-based rare-event search observatory.