U.S. scientists a step closer to finding evidence of dark matter in former gold mine

A U.S. team of researchers hunting for dark matter in a former gold mine in South Dakota, may be getting closer to a major breakthrough in their study after they spent most of their daylight hours in the underground lab over the summer.

The group, led by Yale University physicist Dan McKinsey, has grabbed the interest of peers and governments since the project was first announced, to the point it now involves more than 100 researchers from 17 institutions.

And the first set of key findings will be release in just a few days, said Yale in a statement, during an event at the Sanford Underground Research Facility, which also will be webcast live by South Dakota Public Broadcasting on Oct. 30.

The scientists have been working at the one-of-a-kind laboratory located at the bottom of what was once North America's deepest gold mine, hoping to find more definitive evidence of the mysterious substance estimated to make up as much as 85% of the universe’s total matter.

Experts have inferred dark matter’s existence from the behaviour of known entities, such as galaxies, but they have never detected it directly. This is why teams of researchers around the world are racing to be the first, a collaboration known as the Large Underground Xenon dark matter experiment, or LUX.

“Knowing more about dark matter will give us ideas about the future of our planet, galaxy, and universe,” said a fifth-year graduate student, Nicole Larsen, from the former Homestake gold mine, about 1.6km inside Earth.

U.S. scientists a step closer to finding evidence of dark matter in former gold mine

Yale postdoctoral researcher Markus Horn works on the LUX collaboration's xenon gas system, (Photo by C.H. Faham/Brown University)

“This search has implications for how the universe got to be the way it is and for what’s going to happen to us in the future as well,” she added.

Less than 15% of the universe is made up of conventional matter — protons, neutrons, and electrons. Most of the rest is thought to be dark matter, which cannot be seen or felt, and seems to interact weakly, if at all, with conventional matter. (Hence the nickname for dark matter particles — WIMPs, or weakly interacting massive particles.) Identifying the raw material of the universe is a high priority for physicists and astronomers.

“Dark matter is one of the huge mysteries of modern science,” said team leader McKinsey. “Its effects are widespread in the universe. Knowing its properties would be revolutionary for particle physics.”