A joint Fermilab/SLAC publication

Neutrino velocity consistent with speed of light


Einstein can breathe a sigh of relief – neutrinos obey the cosmic speed limit after all.

Today at the Neutrino 2012 conference in Japan, scientists from experiments around the world announced their most recent measurements of how fast neutrinos travel.  All data point to a neutrino velocity that does not exceed the speed of light.

The measurements confirm that last year’s OPERA result – which seemed to suggest that neutrinos travel faster than the speed of light – was indeed due to instrumental effects.

The new measurements, made by MINOS, which observes neutrinos sent from Fermilab to a mine in Soudan, Minn, and by Borexino, ICARUS, LVD and OPERA, which observe neutrinos sent from CERN to INFN Gran Sasso Laboratory, all support the theoretically predicted time of flight.

“Although this result isn’t as exciting as some would have liked,” CERN Research Director Sergio Bertolucci said in a CERN media update, “it is what we all expected deep down. The story captured the public imagination, and has given people the opportunity to see the scientific method in action – an unexpected result was put up for scrutiny, thoroughly investigated and resolved in part thanks to collaboration between normally competing experiments. That’s how science moves forward.”

Learn more:
CERN statement: Neutrinos sent from CERN to Gran Sasso respect the cosmic speed limit
Fermilab Today article: MINOS reports new measurement of neutrino velocity
INFN statement: Neutrinos sent from CERN to Gran Sasso respect the cosmic speed limit

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