Particles break light-speed limit?

Kevin

http://www.nature.com/news/2011/110922/full/news.2011.554.html

http://arxiv.org/abs/1109.4897v1

http://usersguidetotheuniverse.com/?p=2169

http://news.ycombinator.com/item?id=3027056

Ereditato says that he is confident enough in the new result to make it public. The researchers claim to have measured the 730-kilometre trip between CERN and its detector to within 20 centimetres. They can measure the time of the trip to within 10 nanoseconds, and they have seen the effect in more than 16,000 events measured over the past two years. Given all this, they believe the result has a significance of six-sigma — the physicists' way of saying it is certainly correct. The group will present their results tomorrow at CERN, and a preprint of their results will be posted on the physics website ArXiv.org.

At least one other experiment has seen a similar effect before, albeit with a much lower confidence level. In 2007, the Main Injector Neutrino Oscillation Search (MINOS) experiment in Minnesota saw neutrinos from the particle-physics facility Fermilab in Illinois arriving slightly ahead of schedule. At the time, the MINOS team downplayed the result, in part because there was too much uncertainty in the detector's exact position to be sure of its significance, says Jenny Thomas, a spokeswoman for the experiment. Thomas says that MINOS was already planning more accurate follow-up experiments before the latest OPERA result. "I'm hoping that we could get that going and make a measurement in a year or two," she says.

Perhaps the end of the era of the light cone and beginning of the era of the neutrino cone? I'd be curious to see your probability estimates for whether this theory pans out. Or other crackpot hypotheses to explain the results.

http://www.nature.com/news/2011/110922/full/news.2011.554.html

http://arxiv.org/abs/1109.4897v1

http://usersguidetotheuniverse.com/?p=2169

http://news.ycombinator.com/item?id=3027056

Ereditato says that he is confident enough in the new result to make it public. The researchers claim to have measured the 730-kilometre trip between CERN and its detector to within 20 centimetres. They can measure the time of the trip to within 10 nanoseconds, and they have seen the effect in more than 16,000 events measured over the past two years. Given all this, they believe the result has a significance of six-sigma — the physicists' way of saying it is certainly correct. The group will present their results tomorrow at CERN, and a preprint of their results will be posted on the physics website ArXiv.org.

At least one other experiment has seen a similar effect before, albeit with a much lower confidence level. In 2007, the Main Injector Neutrino Oscillation Search (MINOS) experiment in Minnesota saw neutrinos from the particle-physics facility Fermilab in Illinois arriving slightly ahead of schedule. At the time, the MINOS team downplayed the result, in part because there was too much uncertainty in the detector's exact position to be sure of its significance, says Jenny Thomas, a spokeswoman for the experiment. Thomas says that MINOS was already planning more accurate follow-up experiments before the latest OPERA result. "I'm hoping that we could get that going and make a measurement in a year or two," she says.

The neutrino generation is somewhat indirect. Protons are accelerated into graphite, and then the resulting particles are accelerated further in the correct direction so that they decay into muons and muon neutrinos. The muons are quickly lost (muons don't like to interact with much but a few kilometers of solid rock will block most of them). The detector itself is setup to detect specifically the neutrinos which have oscillated into tau neutrinos.

The detector itself is a series of lead plates with interwoven layers of light-sensitive material which has then scintillator counters to detect events in the light sensitive stuff. I don't fully understand the details for the detector. (In particular I don't know how they are differentiating tau neutrinos hitting the lead plates from muon neutrinos or electron neutrinos) but I naively presume that there's some set of characteristic reactions which occur for the tau neutrinos and not the other two. Since this discrepancy is for neutrinos in general, and they seem to be picking up data for all the neutrinos (I think?) that should't be too much of an issue.

I've heard so far only a single hypothesis of new physics without faster than light travel involving suppression of virtual particles and I don't have anywhere near the expertise to guess if that sort of thing is at all plausible.

The detector itself is a series of lead plates with interwoven layers of light-sensitive material which has then scintillator counters to detect events in the light sensitive stuff. I don't fully understand the details for the detector. (In particular I don't know how they are differentiating tau neutrinos hitting the lead plates from muon neutrinos or electron neutrinos) but I naively presume that there's some set of characteristic reactions which occur for the tau neutrinos and not the other two.

There is a conserved quantity* for elementary particles ... (read more)

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Particles break light-speed limit?

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Particles break light-speed limit?

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