Recent results from the LZ experiment dark matter searches

About

LUX-ZEPLIN (LZ) is the world's most sensitive direct detection experiment to weak-scale dark matter-matter interactions. Using a two-phase time projection chamber containing an active mass of seven tonnes of liquid xenon, the collaboration has published results for a 4.2 tonne-year exposure, achieving world-leading limits and a sensitivity to spin-independent WIMP-nucleon interactions for a $40~\mathrm{GeV/}c^2$ WIMP of $5.1^{-48}~\mathrm{cm}^2$. A follow-up search with the same data set, extending the search window up to $270~\mathrm{keV}$, has yielded one event consistent with a nuclear recoil of $240\pm23(\text{stat})\pm23(\text{syst})~\mathrm{keV}$, which is difficult to explain with any known background, and which corresponded to a $2.6~\sigma$ global significance across the search space. I will describe the LZ data and analysis, with a particular emphasis on the effort to understand and model the high energy nuclear recoil region in light of this result.