This result is really exciting and we’re keen to share the data with the wider academic community for their honest scrutiny. This is rightfully a conservative field so we’re being cautious, but it’s satisfying to know that the tools we helped create and design have contributed to something so significant.”
Dr Jim Dobson
01 September 2026
King's scientists dig into surprising result in search for dark matter
While the signal could be from a well-known dark matter candidate, researchers will need more data to confirm.
New analysis from one of the world’s largest dark matter experiments has recorded an interaction that has so far been unexplained by normal matter.
While the result doesn’t yet meet the statistical threshold needed to claim a discovery it is the most compelling hint of dark matter reported by the LUX-ZEPLIN (LZ) project.
Einstein’s theory of general relativity suggests that dark matter, a so far unknown and unobserved type of matter, could make up as much as 85% of mass in the universe. A key contender for dark matter are WIMPs, or weakly interactive massive particles. These are expected to weigh between the mass of one proton, a subatomic particle present in every atom, and a few thousand protons.
Using a 10-tonne tank of liquid xenon a mile underground in the Sanford Underground Research Facility in South Dakota, physicists from King’s Experimental Particle and Astroparticle Physics group and more than 250 scientists of the LUX-ZEPLIN project capture potential WIMP activity by detecting how potential dark matter particles knock into xenon atoms.
In the latest analysis, the team looked at 220 live days of data collected between March 2023 and April 2024, looking for a higher energy range of possible WIMP interactions than previous analysis.
The King’s team, including PhD students Jed Young, Catherine Lawes and Jasmine Ghamsari, has contributed to preparing data for this kind of analysis, including work to understand and minimise background disturbances. The wider King’s group has also helped ensure the detector is ‘radiopure’, reducing unwanted background, and developed software tools to turn raw observations from the xenon tank into data suitable for analysis
Dr Jim Dobson, Senior Lecturer in Physics who leads the team at King’s and manages one of the experiment’s two data centres that processed the data for the results said: “This result is really exciting and we’re keen to share the data with the wider academic community for their honest scrutiny. This is rightfully a conservative field so we’re being cautious, but it’s satisfying to know that the tools we helped create and design have contributed to something so significant.”
While the results have not reached “5-sigma” significance, the statistical threshold considered a discovery in physics, the new analysis did reach 2.6 sigma, meaning there is approximately a 0.5% chance that the event could be explained by known background noise.
As these potential backgrounds are well understood by the team, with the potential dark matter interaction happening in the centre of the xenon tank, the most sensitive and well understood part of it, the team believe they have taken a robust approach to minimising false positives.
We understand our detector and the backgrounds so well that even a single outstanding event, like the one we found, is important. We expect dark matter events to be extremely rare, so only a handful could mark the first detection of WIMP dark matter.”
Dr Sam Erikson, Senior Research Associate at the University of Bristol
Dr Sam Erikson, Senior Research Associate at the University of Bristol and lead author of the study said: “This was a detailed study in a region we hadn’t explored within this dataset, and we spent months of additional effort to understand all the possible causes of background events. We understand our detector and the backgrounds so well that even a single outstanding event, like the one we found, is important. We expect dark matter events to be extremely rare, so only a handful could mark the first detection of WIMP dark matter.”
In the near future, the team will analyse additional data to test whether the finding continues to grow in significance. LUX-ZEPLIN has already accumulated the world's largest dark matter dataset and will continue to accrue WIMP search data to improve their search statistics.
Dr Albert Baker, who leads on the team's data reconstruction efforts, said: "Whilst this study using the current dataset does not reach discovery significance it is a timely and exciting reminder that LZ, and future xenon detectors, are probing unexplored and meaningful parameter space. Hopefully additional studies with LZ's ever growing exposure can prove to be even more illuminating."
LUX-ZEPLIN is an international project made up of 250 scientists, engineers and support staff and funded by the US, the UK through the Science and Technology Facilities Council, and other countries such as Portugal, South Korea, Australia and Switzerland.
More details of the result can be found in the main collaboration release: https://newscenter.lbl.gov/2026/09/01/lz-sees-surprising-result-in-search-for-dark-matter/
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Lecturer in Physics
PhD student