The ICARUS collaboration - operating a neutrino detector sitting not far from the OPERA experiment in the underground Laboratori del Gran Sasso in Italy - produced a refutation of the superluminality of neutrinos a while ago. That refutation was based on studying the energy spectrum of the neutrinos in the CNGS beam, coming from CERN through a trip of 700 km under the Earth's crust: superluminal neutrinos should have lost some energy due to electroweak radiation, which was not borne out by the data.
The early analysis was only a partial refutation, because one could conceivably argue that superluminal neutrinos possessed additional properties to make them free of the need to comply with electroweak physics. So one could think that the neutrinos detected by ICARUS were also superluminal, but they had not radiated the energy that ordinary Standard Model particles would have, under the same circumstances.
Now, however, ICARUS puts a tombal stone on the whole business. This comes at a time when OPERA has explained they have additional systematic uncertainties in their timing measurement, which will require more time to be tracked down fully. We obviously do not need to wait for that now, since the ICARUS result is perfectly in line with neutrinos being traveling at the speed of light, as they should. Note, neutrinos are massive, but their mass is so small that the difference with a particle moving at exactly the speed of light in vacuum, with a 700km baseline, cannot be detected with our clocks.
The rewsult is described in the paper produced today in the Cornell Arxiv, 1203.3433. The money plot is the following one:
As you can see, the ICARUS result is as expected clustering at δt near zero (where zero means the arrival time of particles moving at the speed of light), while OPERA stands out as a wrong result. As expected.
Now, if your prior belief were that neutrinos may or may not be superluminal, with 50% chance to each hypothesis, you might argue that the two results above are inconclusive: their statistical power is similar, and so the fact that each agrees with a different hypothesis puts the matter in the "totally undecided" field. So people who have argued that scientists are too enamoured with their prior beliefs (of the correctness of basic theory against extravagant variants) may continue to believe that neutrinos are superluminal, that OPERA is correct, and that the ICARUS result above is the wrong one. But I hope that readers of this blog know better...
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- A Dimuon Particle At 30 GeV In ALEPH ??
- Journalists - Please Fact Check Your "Doomsday" News Stories -They Terrify Young Children And Vulnerable People
- DDoS war: How zombie fridges bit the internet in the a$$ today.
- President Obama, Why Humans On Mars Right Now Are Bad For Science
- A Racist On The Jews: Let The Donald Trump!
- Biofuels Are A Climate Mistake
- EPA Again Delays Report On Safety Of Glyphosate
- "The only people who are in for a shock are the people who believe in it, when nothing happens...."
- "Oh, okay, you need to understand a bit about how solar systems form. It starts with a condensing..."
- "Are we gonna be in for a shock with this nibiru planet mr walker also if you had the chance to..."
- "The thing that gets me mr walker is planets can collide so why all of a sudden is this now impossible..."
- "Oh, I saw that comment thanks. I didn't see any point in replying. They gave no reasons, didn't..."
- Placebo: Bubbles Of Nothing Are Still Not Something
- People Who Take Drugs May Be Likelier to Commit Suicide
- Improved 'Screen Time' Guidelines Could Make Parents & Kids Happier
- Dr. Jamie Wells Named One Of America's Top Pediatricians
- Why Did EPA Delay Its Glyphosate Safety Report?
- Scientists Should Fight Postmodern Public Values