Kathmandu— Scientists at the LUX-ZEPLIN experiment in South Dakota have detected a single unexplained particle interaction that resembles a theoretical dark matter particle, though researchers caution it is not yet confirmed as a direct detection of dark matter, marking the closest scientists have come to observing the universe's elusive invisible substance.

Experimental Setup and Findings

Deep beneath the Black Hills of South Dakota, the LUX-ZEPLIN (LZ) experiment uses a tank of ultra-pure liquid xenon surrounded by hundreds of light sensors to detect potential dark matter interactions. The experiment, conducted at the Sanford Underground Research Facility, reviewed 220 days of data collected between March 2023 and April 2024, identifying one event on June 16, 2023, that matches the expected signature of a weakly interacting massive particle (WIMP), a leading dark matter candidate.

Sam Eriksen, lead researcher and a senior research associate at the University of Bristol, emphasized the significance of the single event, stating in a press release that "even a single outstanding event, like the one we found, is important" given the team's thorough understanding of detector backgrounds and potential false signals.

Scientific Context and Significance

Dark matter, which makes up approximately 27 percent of the universe, has been inferred through gravitational effects on galaxy rotation and light bending, but its direct detection has remained elusive since its initial discovery in the 1930s. The LZ experiment's findings represent the most compelling signal yet, with researchers noting that the event has withstood multiple retests and verification attempts.

Theresa Fruth, a physicist at the University of Sydney and a study collaborator, told ABC News that the event is "exciting because it has been re-tested several times and has held up," suggesting it could be a critical step toward confirming dark matter's existence, though scientists remain cautious about premature claims.

Researcher Caution and Next Steps

Rick Gaitskell, the LZ spokesperson and a physicist at Brown University, stressed the need for restraint, stating that scientists "don’t want to get ahead" of themselves and are not claiming to have directly detected dark matter. The team continues to analyze data from the experiment, which involves 250 scientists and engineers from 38 institutions, to determine if the single event is a true dark matter signal or a rare background anomaly.

The findings were presented at the 2026 TeV Particle Astrophysics conference in Japan, where the team outlined their methodology and the rigorous checks applied to the data, underscoring the scientific community's commitment to thorough verification before declaring a discovery.

The LZ experiment will continue collecting data, with researchers hoping to gather more evidence to confirm or rule out the possibility of dark matter detection in future analyses.

(With inputs from Al Jazeera)

Originally published on abcnews.com.np.