Hope for superluminal neutrinos continues to fade

By Hamish Johnston

Physicists working on the ICARUS experiment have reported their first measurement of the speed at which neutrinos travel from CERN to the Gran Sasso lab in Italy – and the particles don’t appear to be moving faster than the speed of light.

That’s the same 730 km journey taken by the famous neutrinos that were clocked at speeds faster than light by the OPERA experiment last year. You may recall that this result generated much speculation about the possibility of superluminal flight – despite the fact that it flies in the face of the special theory of relativity and several other neutrino measurements.

In a brief press release today, Carlo Rubbia, Nobel-prize winner and ICARUS spokesperson, said “ICARUS measures the neutrino’s velocity to be no faster than the speed of light. These are difficult and sensitive measurements to make and they underline the importance of the scientific process.”

CERN Research Director Sergio Bertolucci added “The evidence is beginning to point towards the OPERA [superluminal] result being an artefact of the measurement.”

Interesting, he also said “Whatever the result, the OPERA [collaboration] has behaved with perfect scientific integrity in opening [its] measurement to broad scrutiny, and inviting independent measurements. This is how science works.”

I have no problem with the above statement, but what does bother me is the fact that CERN chose to hype the initial superluminal finding when it first came out last year. I think it’s safe to say that when the news broke in September, most physicists assumed that the result was caused by some sort of systematic error and wondered why CERN was making such a big fuss.

At least CERN has done the right thing by issuing this latest press release – it must have been tempting to keep quiet and hope that the superluminal story would just fade away.

You can read a preprint of the ICARUS result here.