Search for Dark Matter Interactions in an Extended Recoil Energy Window with the LUX-ZEPLIN Experiment
by
Small Seminar Room
Building 510
The LUX-ZEPLIN (LZ) experiment is a dual-phase xenon time projection chamber operating nearly a mile underground at the Sanford Underground Research Facility. With 7 tonnes of liquid xenon and multiple active veto systems, LZ has achieved world-leading sensitivity to Weakly Interacting Massive Particles (WIMPs). Beyond standard spin-independent and spin-dependent interactions, non-relativistic effective field theory predicts dark matter interactions that can produce nuclear recoils at substantially higher energies. In this talk, I will present a recent LZ search extending the nuclear-recoil window to approximately 270 keV using a 2.84 tonne-year exposure. The analysis observed a single event consistent with a 248 keV nuclear recoil, in tension with the background-only model at a global significance of 2.6σ. I will discuss the analysis, the checks performed to scrutinize this event, and the dark matter models tested in this search.