LUX-ZEPLIN dark matter detector records a single unexplained particle event, its most intriguing signal yet
Nearly a mile underground in South Dakota, the LUX-ZEPLIN experiment recorded one particle interaction it cannot explain with known backgrounds. Researchers call it their most compelling hint of dark matter so far, but caution it is a single event at 2.6 sigma, well below the 5-sigma discovery threshold, and not yet peer-reviewed.
The LUX-ZEPLIN (LZ) dark matter experiment, operating nearly a mile underground at the Sanford Underground Research Facility in South Dakota, has recorded a single particle interaction that researchers cannot explain using any known background source. Found in a fresh look at 220 days of data from March 2023 to April 2024, the event sits at 2.6 sigma significance, far short of the 5-sigma threshold physics requires to claim discovery, and was presented at a conference in Japan on September 1st with a paper headed to arXiv and Physical Review Letters, meaning it has not yet passed peer review. LZ will keep collecting data through at least 2028 to see whether the signal strengthens or fades.