UAlbany Physicists Study Unexplained Signal in Dark Matter Search
ALBANY, N.Y. (Sept. 1, 2026) — UAlbany physicists played a central role in analyzing a so-far unexplained anomaly in the data from the world’s most sensitive dark matter detector that offers the most compelling hint yet in the hunt for an unseen building block of the universe.
The new analysis from the LUX-ZEPLIN (LZ) experiment deep inside a former South Dakota gold mine includes a single particle interaction that the researchers so far have been unable to explain with known background signals from normal matter.
The result does not yet meet the statistical threshold required to claim that LZ has discovered direct evidence of dark matter, which would reshape our understanding of physics and how the universe works. But it is a tantalizing clue that they may be looking in the right place.
Read the full announcement from Lawrence Berkeley National Lab.
The missing 85 percent
For the better part of a century, people have been trying to understand dark matter — the invisible substance that almost never interacts with normal matter but is believed to make up roughly 85 percent of the mass in the universe. It has never been directly detected, but physicists believe it must exist based on their observation of the gravitational forces that move galaxies. Determining exactly what dark matter is and how it behaves would revolutionize our understanding of the universe.
“These latest results from LZ are truly exciting, but we also have to be careful not to get ahead of ourselves,” said Associate Professor of Physics Cecilia Levy, one of several UAlbany researchers working on the LZ project. “The LZ collaboration has gone to extraordinary lengths to try to find a mundane explanation for what we saw in the data. At the end of the day, for now, it’s just one event. But we already have so much more data to look at, which should be able to tell us whether what we’re seeing is just a statistical fluctuation or the first hint of something never before seen by humans.”
LZ is an international collaboration of 250 scientists and engineers from 39 institutions. The detector is managed by the U.S. 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 experiment uses 10 tonnes of ultrapure liquid xenon to search for dark matter and is optimized to look for WIMPs, or weakly interacting massive particles.
Searching for a signal in the noise
Specifically, researchers are looking for the light and electrical charges caused by the collisions of these theorized WIMPs and the nuclei inside the Xenon atoms. They built the LZ detector at the bottom of a mine to filter out as much cosmic interference as possible in hopes of being able to clearly attribute any interactions detected to collisions caused by dark matter.
In addition to a mile of rock above it, the LZ experiment uses multiple methods to prevent or account for particle interactions caused by normal matter, including a water tank and outer detectors that protect the central detector from background neutrons and a suite of computational tools that disentangle particle interactions and reject dark matter mimics.
“UAlbany scientists drove the development of the simulation software, known as NEST, used in the LZ experiment,” said Associate Professor of Physics Matthew Szydagis, who is also working on the LZ project. “By combining advanced computer simulations with cutting-edge new calibrations of the LZ detector, UAlbany physicists’ contributions were instrumental in improving researchers’ abilities to distinguish potential background signals due to different types of known subatomic particles from possible dark matter.”
An 'anomalous event'
The anomalous event was detected in data collected between March 2023 and April 2024. If it was caused by dark matter, the WIMP that generated it would likely have a mass of at least 200 GeV/c2 (gigaelectronvolts), or more than 200 times the mass of a proton. It would also suggest a specific type of interaction between WIMPs and ordinary matter beyond the simplest model. The LZ results have not reached “5-sigma” significance, the statistical threshold considered a discovery in physics. The new analysis is 2.6 sigma, meaning there is approximately a 0.5% chance that the event could be explained by known backgrounds.
With additional data, researchers can test whether the finding continues to grow in significance or fades away. LZ has already accumulated the world's largest dark matter dataset and will continue to accrue WIMP search data at SURF, substantially improving their search statistics.
The new results were presented in a scientific talk at the 2026 TeV Particle Astrophysics conference in Japan. The paper will be released on the online repository arXiv and submitted to the journal Physical Review Letters.