World’s most sensitive dark matter detector yields new, exciting results

Already touted as the most sensitive dark matter detector on the planet, the Large Underground Xenon (LUX) experiment in South Dakota has been tweaked, and will now apparently do an even better job of hunting for the unseen substance believed to make up most of the universe.

According to the US Department of Energy’s Lawrence Berkeley National Laboratory’s National Energy Research Scientific Computing Center, which runs LUX along with officials from Brown University’s Center for Computation and Visualization, new calibration techniques employed by scientists working with the detector has “dramatically” improved its sensitivity.

The LUX detector, which is housed underground at the Sanford Underground Research Facility in the Black Hills of South Dakota, is used by scientists to search for a type of particle known as WIMPs (weakly interacting massive particles) that are believed to be dark matter candidates.

“We have improved the sensitivity of LUX by more than a factor of 20 for low-mass dark matter particles, significantly enhancing our ability to look for WIMPs,” Brown physics professor Rick Gaitskell, co-spokesperson for the experiment, said in a statement. “It is vital that we continue to push the capabilities of our detector in the search for the elusive dark matter particles.”

Closer than ever to discovering WIMPs

Scientists involved with the experiment report that the improvements made to LUX have made it possible for them to test additional particle models of dark matter, and makes it possible for them to exclude some previous candidates. While dark matter has never been directly detected, experts are confident that it exists because of the way it bends light in the universe.

Likewise, WIMPs are only believed to interact with other matter in extremely rare cases, and like dark matter itself, they have yet to be directly detected. Following an initial three-month run, the LUX scientists have decided to use new calibration techniques that should enable them to search for particles that they did not previously know would be visible to the detector.

Their findings, which have been submitted to the journal Physical Review Letters, involved the re-examination of data collected during that initial three-month run in 2013, and helps eliminate what were previously categorized as potential dark matter detections at low-mass ranges.

While the detector has yet to pinpoint a dark matter signal, it has enabled researchers to rule out all but vast mass ranges where dark matter particles could exist, the study authors said. With the new calibrations, its improved sensitivity should bring them even closer to findings WIMPs.

“The search continues,” explained Dan McKinsey, a physics professor at UC Berkeley and co-spokesperson for LUX. “LUX is once again in dark matter detection mode at Sanford Lab. The latest run began in late 2014 and is expected to continue until June 2016. This run will represent an increase in exposure of more than four times compared to our previous 2013 run. We will be very excited to see if any dark matter particles have shown themselves in the new data.”


Feature Image: Matthew Kapust/Sanford Underground Research Facility