Another day, another particle. Unlike the Higgs boson, the neutral Xi_b baryon is not expected to solve any deep, outstanding mysteries. But, sightings of its excited state are another first for the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland.
The Xi_b, a conglomerate of quarks, was previously seen by the now-defunct Tevatron collider at Fermilab in Batavia, Illinois, but only in its lowest energy state.
Theory says the particle has higher energy states that decay rapidly into a zoo of lower-mass muons, pions and protons. These are tough to spot in the LHC’s particle detritus but can be used to confirm the presence of excited Xi_bs.
The team at , one of the LHC’s two main detectors, now reports piecing together . The result has a statistical significance greater than 5 sigma, meaning there is less than 1-in-a-million chance that it’s a fluke.
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“The significance is that you are able to find these states in the very complicated environment of the LHC,” says CMS’s .
“It fills in another little hole where there was a ‘hasn’t been seen yet’ in the drawing of predicted things,” he says.
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