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[link] Faster than light neutrinos due to loose fiber optic cable.

13 betterthanwell 22 February 2012 09:52PM

A mundane cause for a surprising result. Consider this unconfirmed for now, however unsurprising it sounds. 

According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos' flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed. Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. 

New data, however, will be needed to confirm this hypothesis.

Source: Science/AAAS

OPERA Confirms: Neutrinos Travel Faster Than Light

10 XiXiDu 18 November 2011 09:58AM

New high-precision tests carried out by the OPERA collaboration in Italy broadly confirm its claim, made in September, to have detected neutrinos travelling at faster than the speed of light. The collaboration today submitted its results to a journal, but some members continue to insist that further checks are needed before the result can be considered sound.

Link: nextbigfuture.com/2011/11/faster-than-light-neutrinos-opera.html

The OPERA Collaboration sent to the Cornell Arxiv an updated version of their preprint today, where they summarize the results of their analysis, expanded with additional statistical tests, and including the check performed with 20 additional neutrino interactions they collected in the last few weeks. These few extra timing measurements crucially allow the ruling out of some potential unaccounted sources of systematic uncertainty, notably ones connected to the knowledge of the proton spill time distribution.

[...]

So what does OPERA find ? Their main result, based on the 15,233 neutrino interactions collected in three years of data taking, is unchanged from the September result. The most interesting part of the new publication is instead that the  find that the 20 new neutrino events (where neutrino speeds are individually measured, as opposed to the combined measurement done with the three-year data published in September) confirm the earlier result: the arrival times appear to occur about 60 nanoseconds before they are expected.

Link: science20.com/quantum_diaries_survivor/opera_confirms_neutrinos_travel_faster_light-84763

Paper: kruel.co/paper-neutrino-velocity-JHEP.pdf

Previously on LW: lesswrong.com/lw/7rc/particles_break_lightspeed_limit/