The University of Tokyo, Kamioka Observatory, the Super-Kamiokande Experiment A researcher stands inside the Super-Kamiokande detector where physicists have confirmed that they observed the changing of muon neutrinos into electron neutrinos. Download image

Tiny neutrino that could solve cosmic mystery is observed shifting form

Scientists from Japan, UC Irvine and elsewhere today confirmed they have documented muon neutrinos transforming into electron neutrinos. The breakthrough could help explain “one of the most profound mysteries in science,” according to the group – why the universe is full of matter but not anti-matter. The finding was announced today at the European Physical Society meeting in Stockholm by the international T2K (Tokai to Kamioka) collaboration, named for two Japanese villages that are hubs of a decades-long experiment to track the invisible neutrinos. The project, temporarily crippled by the devastating March 2011 earthquake, shoots a beam containing muon neutrinos produced in the Japan Proton Accelerator Research Complex on the east coast of Japan some 295 kilometers (185 miles) through the Earth to the gigantic Super-Kamiokande underground detector near the city of Toyama. Data analysis has revealed nearly four times more electron neutrinos than expected. The probability that random statistical fluctuations alone would produce the observed excess of electron neutrinos is less than one in a trillion. “This is a big deal,” says UC Irvine physicist Henry Sobel, U.S. co-spokesperson for Super-Kamiokande, where it was first documented that neutrinos have a mass in 1998. Neutrinos were discovered by UC Irvine’s Frederick Reines, who won a Nobel Prize for his work. For more information, see http://t2k-experiment.org

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