Dark matter experiment deep in US gold mine returns first results

A new dark matter detector almost a mile deep in a former South Dakota gold mine has yielded its first data, scientists report. The goal of the Large Underground Xenon experiment is to identify the nature of dark matter, an invisible substance believed to be all around us, making up most of the matter in the universe but barely affecting our every-day lives, they said. Scientists published the first results from the experiment Wednesday, which they said validate the experiment's design and performance in its search to uncover the exact identity of the dark matter particle. Scientists compare that search to the hunt for the Higgs boson particle carried out by the Large Hadron Collider in Switzerland. Work on the detector started in 2008 and the experiment was ready for an initial run earlier this year. Some of the world's most sensitive equipment has been installed in the mine's extremely sheltered environment, looking for tiny and extremely rare flashes of light that would indicate a collision between a dark matter particle and a normal matter particle. "These instruments take many years to build and we are always pushing new technologies to the limit," said physicist Henrique Araujo from Imperial College London, one of the institutions taking part in the international effort. "It is very significant that LUX worked as designed when we finally pushed the 'on' button," he said in an ICL release Wednesday. "Many experiments never reach this stage." The experiment's prime purpose, the scientists said, is to detect Weakly Interacting Massive Particles, or WIMPS, considered the prime candidates to constitute the dark matter in our galaxy and in the universe. "LUX has significantly higher sensitivity than the previous world's best dark matter experiments -- especially for the lightest WIMPs, which cause the faintest signals," Araujo said.