Faculty and student researchers from Brown contributed key expertise on the LZ team's latest findings, refining the search for dark matter particles and pushing the boundaries of detection technology.
PROVIDENCE, R.I. [Brown University] - Dark matter is one of the biggest mysteries in physics and cosmology. Though it can't be seen directly, scientists suspect it's what holds galaxies together and makes up about 85% of all mass in the universe.
A global team of over 250 scientists and engineers from 38 institutions - led by Lawrence Berkeley National Laboratory and including students, postdoctoral researchers and faculty from Brown University - are part of a worldwide effort to understand the true nature of dark matter and catch a glimpse of this elusive substance for the first time. They use a highly sensitive detector to look for tiny flashes of light that might occur when dark matter particles interact with atoms in the detector. While they don't reveal the existence of dark matter, their latest results show that the team has been getting closer than any team of scientists to date.
Presented on Monday, Aug. 26, at conferences in Chicago and São Paulo, Brazil, the new results offer important insights into WIMPs, which are the leading theoretical candidates for comprising dark matter. Short for weakly interacting massive particles, WIMPs can't be seen because they don't absorb, emit or reflect light. And they interact with normal matter only on rare occasions, which is why they're so hard to detect even when millions may be traveling through the Earth and everything on it each second.
After analyzing nearly 300 days of data from the LUX-ZEPLIN (LZ) dark matter detector, researchers have refined their search for these elusive particles, exploring weaker dark matter interactions than ever explored before. The key finding is that the team came up with no evidence for WIMP signals above a mass of 9 gigaelectronvolts/c2, a measurement roughly equivalent to nine times the weight of a proton. It suggests WIMPs are interacting with matter at weaker levels than previously thought.
"Our goal is to improve our search even further with an even better level of sensitivity," said LZ experiment cofounder Richard Gaitskell, a Brown professor of physics and director of the Center for the Fundamental Physics of the Universe. "The detector is very ready to see a signal."
