Another faster-than-light neutrinos challenge

October 1, 2011 by Amara D. Angelica

This just in: a new critique of the CERN OPERA finding of faster-than-light neutrinos. In “New Constraints on Neutrino Velocities,” Cohen and Glashow argue that the high-energy (17.5 GeV) superluminal muon neutrinos would actually lose energy rapidly (down to about 12.5GeV) on the 730km trip, long before arriving in Italy.

Cherenkov radiation (credit: Wikimedia Commons)

But that didn’t happen. Ergo, the neutrino weren’t really traveling faster than light, say Cohen and Glashow. So how would they lose energy? By bremsstrahlung (conversion of neutrino energy to light, as seen in Cherenkov radiation in nuclear reactors).

Neutrino physicist Dr. Ben Still’s Neutrino Blog has a lucid explanation. Also see his description of why the supernova explosion in 1987 didn’t show evidence of faster-than-light neutrinos, Supernova Neutrinos in 1983 and 1987?, and his critique of the OPERA experiment: Not Feeling Very Energetic.