Scientific progress goes "oops" —

“We’ve observed a new particle”: leaked video reveals Higgs confirmation

Mass, decay into two photons tell the tale.

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Two superconducting dipole magnets used in the LHC

"We've observed a new particle." That's the opening statement in a video featuring Joe Incandela, the spokesman for the Large Hadron Collider's CMS detector. The video, first spotted by ScienceNews, was publicly accessible on the CERN website earlier today, but has now apparently been pulled. It appears to preempt the big announcement scheduled for early tomorrow morning, and implies that this year's data was enough to push the evidence for the Higgs past the five standard deviations needed to declare discovery.

"When we say we've observed the particle, it means we've just got enough data to say it's definitely there, and it's very unlikely to go away," Incandela says in the video. He went on to say that we know it's a boson because it decays into two photons. Its mass is roughly 130 times that of the proton, making it the heaviest boson we've discovered so far—and the heaviest particle other than the top quark.

According to the video, the two-photon decay is one of the strongest bits of evidence and provides a narrow peak that helps define its mass. Strong evidence is also available through decay into two Z particles; the signal is there in other decay channels as well, which is reassuring, but those are less definitive because of the background noise present.

Combined with the results of last year's search, this pretty much nails down the Higgs at roughly 125GeV, although there still may be some interesting details during tomorrow's official announcement. And, as we predicted yesterday, Incandela is already talking about how we need to produce more of these to see whether this particle behaves like we'd predict for a Standard Model Higgs boson.

In the meantime, Incandela seems to be ready to celebrate—provided he's given the time for a nap first: "We're very excited. I'm extremely tired at the moment, so I may not appear to be as excited as I really am."

UPDATE: CERN has told a UK journalist that the CMS team has made videos covering all possible results, and only the one announcing discovery has leaked.

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