One of the teams hunting the Higgs boson at the Large Hadron Collider says it has pinned down the particle so conclusively that there's only a one-in-300 million chance it does not exist. When the team announced that it had discovered the Higgs on July 4, it said it had achieved only a "5 sigma" level of certainty, the minimum to claim a discovery, the BBC explains. That amounts to a one-in-3.5 million chance the particle doesn't exist.
It's impossible to directly observe the particle, which exists for only a fraction of a second before decaying into something else. But the team has been conducting more analysis on these "decay channels," and as a result has boosted its certainty up to 5.9 sigma. Still, the particle may not be the exact Higgs boson theorists have always imagined; the researchers have been careful at all turns to call it only a "Higgs-like" particle until more analysis can be done.