A surprising result in the search for high-energy dark matter interactions with the LUX-ZEPLIN (LZ) dark matter experiment

by David Woodward (Lawrence Berkeley National Laboratory)

Tuesday Sep 22, 2026, 3:00 PM → 4:00 PM Pacific/Honolulu

Room 420 (Watanabe Hall)

LZ is a dark matter experiment operating at the Sanford Underground Research Facility in Lead, SD. The experiment is centered on a time projection chamber (TPC) that utilizes a 7-tonne liquid xenon target to directly observe possible dark matter interactions, along with two veto detectors to tag backgrounds. LZ has previously published world-leading limits on Weakly Interacting Massive Particles (WIMPs), assuming interactions that produce low-energy nuclear recoils in the energy range O(1-10 keV). However, some models predict interactions where low-energy scatters are suppressed and high-energy nuclear recoils (> 100 keV) are dominant, a region where LZ has particularly low background rates. In this talk, I will describe a recent analysis of 220 live days of LZ data that found a single event consistent with a ~250 keV nuclear recoil, in significant tension with our background models.

UHSeminar_DavidWoodward.pdf

video-Dr. D. Woodward