By Ron Cowen
Physicists have uncovered what looks like a quantum conspiracy in one of the first results from the Large Hadron Collider, the world’s most powerful atom smasher.
A larger than expected number of charged particles generated during the LHC’s highest energy collisions are doing something they have no business doing. Instead of flying away from the collision site in random directions, these particles are somehow paired, moving away from the point of impact at similar angles and ending up at opposite ends of the collider’s CMS detector.
It’s as if some of the particles “managed to talk to each other” immediately after their creation and stayed in contact while zooming off in opposite directions at close to the speed of light, says Gunther Roland of MIT, a collaborator on the collider’s compact muon solenoid experiment. There’s no obvious explanation for the puzzling finding, he adds.
Roland and Guido Tonelli of the University of Pisa and the National Institute of Nuclear Physics in Italy presented the results September 21 at CERN, the European physics lab that operates the LHC near Geneva. The researchers and their colleagues also posted their findings September 22 on arXiv.org.
The team made the discovery, never before seen in interactions between energetic protons, after analyzing some 350,000 high-intensity collisions recorded between this past March and August, when the collider’s twin proton beams reached half their maximum energy. Among high-energy proton collisions that generate 100 or more charged particles, only a few percent of the particles show the correlation effect, Tonelli says.