Not-So-Fast: Neutrinos Travel At Speed of Light, Says Icarus Experiment at Gran Sasso

Neutrinos seem to be travelling at speed of light once more! A different experimental group – the Icarus group, tried out the same experiment as the OPERA group in the same lab, but using different equipment and found that the speed of the neutrinos was very much compatible with the speed of light within experimental error bounds! The Icarus group have found that neutrinos travel at the speed of light, not faster. The OPERA result, already fraught by reports of device malfunctions, has received another jolt.

The Icarus Experiment

The experimental findings of the Icarus group, also based in Gran Sasso just like OPERA, and also receiving neutrinos from the same CERN source, were published in a paper which is available online here.

The T600 detector

A second opinion

The Icarus group intends on studying the different properties of neutrinos and also aspects of any proton decay. They use a Liquid Argon Detector – the T600 – which uses 600 tonnes of liquid nitrogen to detect the presence of neutrinos and also measure their direction and momentum. They have been tweaking their experiment so as to be able to re-check OPERA’s claim.

Of course, OPERA itself has been in a soup with its own problems. We reported the initially reported error of an optical fibre delay here and then followed up with yet another error that might have influenced the speed. With so much at stake, the littlest things might compromise the findings of the biggest experimental groups.

Icarus says that there are more tests to come – as many as four more experiments intend to verify OPERA. The entire physics community is expecting negative results, akin to Icarus’, but to be sure of such a thing would be prejudice.

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Debjyoti Bardhan

Is a science geek, currently pursuing some sort of a degree (called a PhD) in Physics at TIFR, Mumbai. An enthusiastic but useless amateur photographer, his most favourite activity is simply lazing around. He is interested in all things interesting and scientific.