Future and its affiliate partners may earn a commission when you purchase through links on our articles.
Simulation of a cluster of galaxies (middle) connected by gas (right) and invisible dark matter (left). One of the largest dark matter searches ever conducted has just concluded. |Image source: European Space Agency
A record-breaking investigation using a particle detector a mile underground in South Dakota may reveal something about dark matterthis mysterious substance is thought to make up most of the matter in the universe.
The experiment, called LUX-ZEPLIN (LZ), uses the largest data set of its kind to constrain the potential properties of one of the leading candidates for dark matter with unprecedented sensitivity. The study found no evidence of this mysterious substance, but will help future studies avoid false detections and better study this poorly understood part of the universe.
“This mission is trying to solve this huge problem, this huge missing problem in our understanding of the universe,” Rick Gaitskellwho heads the Particle Astrophysics Group at Brown University and is a member of the LZ research team, told Live Science .
result, Published on Monday (December 8), has been submitted to the journal Physical Review Letters and is available as a preprint via arXiv. The results were also presented during a scientific presentation at the Sanford Underground Research Facility, where the LZ detector is located.
WIMPs and Neutrinos
The team’s new research has two goals: elucidate the characteristics of low-mass The “flavor” of dark matter particles called Weakly Interacting Massive Particles (WIMPs), and see if the detectors can observe solar neutrinos—nearly massless subatomic particles produced by nuclear reactions inside the sun. The team suspects the detection signatures of these particles may be similar to those predicted by some dark matter models, but would need to find solar neutrinos to know for sure.
The LUX-ZEPLIN main detector is installed underground in the surface laboratory. |Image credit: Matthew Kapust/Sanford Underground Research Facility
The experiment, which lasted 417 days between March 2023 and April 2025, followed an upgrade in the detector’s sensitivity to look for rare interactions with elementary particles. The cylindrical chamber filled with liquid xenon is the theater of action. Researchers can observe collisions of weakly interacting particles or neutrinos with xenon, both of which produce flashes of photons as well as positively charged electrons.
The experiment advances the science of weakly interacting particles and neutrinos. As for neutrinos, researchers have increased their confidence that a type of solar neutrino called boron-8 is actually interacting with xenon. This knowledge will help future studies avoid false detections of dark matter.
Physical findings usually must reach a confidence level known as “5 sigma” to be considered valid. The new work achieved 4.5 sigma—a considerable improvement over the sub-3 sigma results reported by both detectors last year. This is especially noteworthy considering that the detector only detects boron-8 about once a month, even when monitoring 10 tons of xenon, Gaitskell said.
As for the dark matter problem, however, the researchers did not find any clear information about the low-mass type of weakly interacting particles they were looking for. Scientists would know this if they saw it, the team says; if a WIMP strikes the center of a xenon molecule, the energy of the collision would create a unique signature, just as the model predicts.
“If you take a nucleus, dark matter can come in and actually scatter out of the entire nucleus at the same time and cause it to recoil,” Gaitskell explained. “It’s called coherent scattering. It has a special signature in xenon. So we’re looking for those coherent nuclear recoil forces.”
The team did not detect this signature in their experiments.
double run
Another longer run will begin in 2028, when the detector is expected to collect results for a record-breaking 1,000 days. Longer run times give researchers a better chance of capturing rare events.
The detector will not only look for more solar neutrinos or WIMP interactions, but also for other physical phenomena that may be beyond detection range. Standard model It is said to describe much of the environment around us.
Related stories
—Do NASA telescopes really “see” dark matter? Strange gamma rays spark bold claims, but scientists urge caution
—Ghost galaxies without dark matter confuse astronomers
— A mysterious light at the center of the Milky Way could reshape a major cosmological theory
Gaitskell emphasized that the role of science is to keep moving forward even if there are “negative” results.
“One thing I’ve learned is never assume that nature does things exactly the way you think it should,” said Gaitskell, who has been studying dark matter for more than four decades.
“There are many elegant [solutions] You say, ‘That’s beautiful. This must be true. We tested them… and it turned out that nature ignored it, and nature didn’t want to go that particular route. “