Date: Sunday, 20-November-2011, 10:01 AM | Message # 2
Faster-than-light neutrinos pass test
By Alan Boyle
Researchers say new tests have confirmed earlier indications that neutrinos can travel faster than light, but not everyone is convinced.
The claim runs so counter to a century's worth of physics that most observers won't be content until the findings from the OPERA experiment are repeated under a variety of conditions, by different teams of researchers. If the results hold up, that would require a reinterpretation of Albert Einstein's special theory of relativity, which effectively sets the velocity of light in a vacuum as a cosmic speed limit.
The latest round of tests was conducted to address some of the criticisms that cropped up in the wake of the OPERA team's initial announcement about faster-than-light neutrinos in September.
"A measurement so delicate and carrying a profound implication [for] physics requires an extraordinary level of scrutiny," Fernando Ferroni, president of the Italian Institute for Nuclear Physics, or INFN, said in a news release. "The experiment OPERA, thanks to a specially adapted CERN beam, has made an important test of consistency of its result. The positive outcome of the test makes us more confident in the result, although the final word can only be said by analogous measurements performed elsewhere in the world."
"OPERA" is a tortured acronym that stands for "Oscillation Project with Emulsion-tRacking Apparatus." The team's researchers shoot beams of neutrinos from the CERN particle-physics center on the French-Swiss border to INFN's Gran Sasso Laboratory, more than 450 miles (730 kilometers) away. The travel time for each pulse of neutrinos is measured to an accuracy of billionths of a second. In the faster-than-light experiment, the researchers reported that the neutrinos arrived 60 nanoseconds earlier than a light beam would have.