Scientists looking for invisible dark matter can't find any

WASHINGTON -- Scientists have come up empty-handed in their latest effort to find elusive dark matter, the plentiful stuff that helps galaxies like ours form.

For three years, scientists have been looking for dark matter -- which though invisible, makes up more than four-fifths of the universe's matter -- nearly a mile underground in a former gold mine in Lead, South Dakota.

But on Thursday, they announced at a conference in England they didn't find what they were searching for, despite sensitive equipment that exceeded technological goals in a project that cost $10 million to build.

"We're sort of proud that it worked so well and also disappointed that we didn't see anything," said University of California, Berkeley physicist Daniel McKinsey, one of two scientific spokesmen for the mostly government-funded project.

The mine project, called Large Underground Xenon experiment or LUX, was one of three places looking for dark matter.

Another is on the International Space Station, and a third is an effort to create dark matter at the Large Hadron Collider, run by the European consortium that found the Higgs Boson particle.

At the South Dakota site, more than 4,800 feet of earth helped screen out background radiation.

Scientists used a large vat of liquid xenon they hoped would produce a flash of light when weakly interacting massive particles, or WIMPS, bounced off the super-cooled liquid.

Not finding WIMPS may drive physicists to think about new candidates for dark matter, even though WIMPS are still the most viable option, said Neal Weiner, director of the Center for Cosmology and Particle Physics at New York University, who was not part of the research.