Five out of five experiments agree: neutrinos do not travel faster than the speed limit.
Or more precisely: to within the uncertainties of current measurements, neutrino speed, for neutrinos with energies far larger than their masses, is experimentally indistinguishable from the speed of light in vacuum. This is just as expected in standard Einsteinian special relativity, which would predict they move just below light speed, by an amount too small to measure with current experiments.
Based on data taken in May 2012 using a beam of neutrinos sent from the CERN laboratory to the Gran Sasso lab, the four experiments ICARUS, LVD, Borexino and even OPERA (the source of all the excitement) find results consistent with the speed of light, with uncertainties (at one-standard-deviation) about 10 times smaller than OPERA’s original measured deviation of neutrino speed from the speed of light. The new results are consistent with ICARUS’s result from 2011 data. Moreover, OPERA’s mistaken result from September and November 2011 — a claimed six standard deviations away from the expected speed — has now been corrected, following their detective work presented in March. Even MINOS, a U.S. experiment, has revised their older result, which was previously slightly discrepant from the speed of light by a small amount (two standard deviations), and they find now that their data too are quite consistent with neutrinos traveling with light speed, though with much less precision in the measurement.
And so with a final quintet, sung in unison, this melodramatic comic OPERA buffa comes to a close. As with all classic operatic comedies, there’s been crisis, chaos, and a good bit of hilarity, all the while with wise voices speaking reason to no avail, but in the end the overzealous are chastened, the righteous are made whole, everyone (even the miscreant) is happy, and all is well with the world.
Curtain!! Applause!! Science Triumphant!!
Favorable review to follow when time permits.