Well, we weren't involved in this, but we will be. To quote from a Science article with our experiment spokesman:
> Chang Kee Jung, a neutrino physicist at Stony Brook University in New > York, says he'd wager that the result is the product of a systematic > error. "I wouldn't bet my wife and kids because they'd get mad," he > says. "But I'd bet my house." > > Jung, who is U.S. spokesperson for a similar experiment in Japan > called T2K, says the tricky part is accurately measuring the time > between when the neutrinos are born by slamming a burst of protons > into a solid target and when they actually reach the detector. That > timing relies on the global positioning system, and the GPS > measurements can have uncertainties of tens of nanoseconds. "I would > be very interested in how they got a 10-nanosecond uncertainty, > because from the systematics of GPS and the electronics, I think > that's a very hard number to get." And we're already being cited as a logical source for a test of these results. Quoting the HEP trade mag "SymmetryBreaking": > Two other long-baseline neutrino experiments, one in the United States > and the other in Japan, could double-check OPERA's results. The MINOS > experiment sends a beam of neutrinos from Fermi National Accelerator > Laboratory into a 6,000-ton detector in a former iron mine about 450 > miles away in northern Minnesota. The T2K experiment studies neutrinos > that travel more than 180 miles through Japan from Tokai to Kamioka. However, the Opera experiment uses tau neutrinos, while we and MINOS both use muon neutrinos, which may be why we haven't noticed the effect, Although, not having any expectation of needing to do so, it's not clear at the moment (ie I don't know) if we even have the resolution capability built in to our system yet to detect an effect at that timing accuracy. Plots of the "beam buckets" associated with our detected neutrinos are graphed with a microsecond scale, not nanosecond, because the buckets (an artifact of the mechanics of the accelerator producing the particles) are in clusters of eight, each about 0.6 microseconds apart, every three seconds, so the usual display is of a five microsecond interval. Unless an obvious reason for the discrepancy turns up in the next few weeks, I imagine we'll be either reanalysing data or reworking our detector electronics in order to post a result of our own timing investigation (if the latter, we'll have to wait til next year when the accelerator is finshed being repaired after the quake). Um, a sense of the speculation about this runs strongly in favour of some sort of measurement error, though that doesn't prevent musings about how it could be true. The chief suspect for the latter is the "sterile" neutrino, an object whose existence has been hinted in experiments by a few persistent low counts, not yet enough to be a solid indication, which suggest that it may be possible that the neutrinos, during their oscillations from type to type while in flight, can pass through a state which has no interaction with normal matter. It could be that this state also flicks into a condition of mathematically "imaginary" mass, which would allow superluminal velocity. The problem is that passing through light speed on the way to this condition is not allowed, so it would have to involve some pretty exotic transformation; of course anything at that point is pretty exotic... -Pete On Fri, 23 Sep 2011, Ray Harrell wrote: > Congratulations to Pete and all of the scientists at CERN on their new world > shaking operatic production. My wife got me up this morning after reading > about it at the Cornell site. She said: "It's a whole new world." > > > > Ray Evans Harrell > > The Magic Circle Opera Repertory Ensemble. Inc. > > Jewish Theological Seminary > > _______________________________________________ Futurework mailing list [email protected] https://lists.uwaterloo.ca/mailman/listinfo/futurework
