Researchers with the LUX-ZEPLIN (LZ) experiment, a global dark matter search that includes Black Hills State University researchers, announced their latest findings on Monday, Dec. 8. The newest results from LZ extend the experiment’s search for low-mass dark matter and set world-leading limits on one of the prime dark matter candidates: weakly interacting massive particles, or WIMPs. They also mark the first time LZ has picked up signals from neutrinos from the sun, a milestone in sensitivity.
LZ is an international collaboration of 250 scientists and engineers from 37 institutions. The detector is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and operates nearly one mile below ground at the Sanford Underground Research Facility (SURF) in South Dakota.
The new results use the largest dataset ever collected by a dark matter detector and have unmatched sensitivity. The analysis, based on 417 live days of data that were taken from March 2023 to April 2025, found no sign of WIMPs with a mass between 3 GeV/c2 (gigaelectronvolts/c2), roughly the mass of three protons, and 9 GeV/c2. It is the first time LZ researchers have looked for WIMPs below 9 GeV/c2, and the world-leading results above 5 GeV/c2 further narrow down possibilities of what dark matter might be and how it might interact with ordinary matter. The results were presented today in a scientific talk at SURF and will be released on the online repository arXiv. The paper will also be submitted to the journal “Physical Review Letters.”
Faculty and students at BHSU play a key role in this research through the BHSU Underground Campus located at level 4850’ of SURF. Utilizing ultra-sensitive screeners, BHSU researchers determine the background radiation levels of different components of the LZ detector. These background levels then feed into the background model for LZ, which helps determine its world-leading sensitivity.
“Students at BHSU have the rare opportunity to participate in world-leading experiments a mile underground at SURF,” said Dr. Brianna Mount, associate professor of Physics and lab director at the BHUC. “The physics group at BHSU is excited and honored to contribute to this exciting announcement and look forward to future years of success with the LZ experiment and all its collaborators."
Over the past decade, more than 30 BHSU students have conducted underground research at the Black Hills Underground Campus (BHUC), many contributing directly to LZ’s counting efforts. Recent Department of Energy funding has fueled growth in BHSU’s physics program, enabling the addition of new faculty and a postdoctoral researcher within the past year. These positions will afford BHSU continued opportunities to aid in the advance of the search for dark matter on experiments like LZ.
“The BHUC will continue to be an important tool to dark matter searches and neutrino experiments in this exciting time for physics,” Mount added.
Additional details on the LZ experiment and the latest results are available in this release from Lawrence Berkeley National Laboratory.