Thursday, August 16, 2012

Yes Virginia, There Are No Superluminal Neutrinos

Not wanting to to beat a dead horse, even though we already have sufficient confirmation that the original OPERA result is faulty. Still, a new paper published in PRL this week kinda sealed the deal[1]. They measured the speed of muon neutrinos from CERN to their detector in Gran Sasso, which is practically the identical situation as OPERA. So what did they find? Here's the abstract:

Abstract: We report the measurement of the time of flight of ∼17  GeV νμ on the CNGS baseline (732 km) with the Large Volume Detector (LVD) at the Gran Sasso Laboratory. The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a tightly bunched-beam structure to allow the velocity of neutrinos to be accurately measured on an event-by-event basis. LVD has detected 48 neutrino events, associated with the beam, with a high absolute time accuracy. These events allow us to establish the following limit on the difference between the neutrino speed and the light velocity: -3.8×10-6<(vν-c)/c<3.1×10-6 (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements.
Yup. No superluminal neutrinos!


[1] N. Yu et al., Phys. Rev. Lett. v.109, 070801(2012).

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