What scientists found in December was that two detection systems, one called ATLAS and the other called CMS, found a curious bump in the plots of energy versus "events." (Events are essentially detections of photons or particles.)So CMS kept looking.
The bump was large enough that it looked interesting to scientists. If real, it could have been evidence of a particle nobody has seen before at energies of 750 billion electron volts (GeV). During the LHC's current run, it can reach energies of almost 13 trillion electron volts (TeV).
But now, new data from CMS, collected since December, shows that the 750 GeV bump was likely an illusion — a statistical artifact of the kind that sometimes crops up in experiments like this, said Michael Peskin, a theoretical physicist at the SLAC National Accelerator Laboratory. [Beyond Higgs: 5 Elusive Particles That May Lurk in the Universe]
Even back in December, some physicists — Peskin among them — had doubts. He noted the teams working on the LHC issued a statement that said, effectively, they weren't issuing one. "The statement said the statistical significance was too low to report an observation," Peskin said.
But that doesn't mean it's a useless result, Strassler said. Nor does it mean the spate of papers theorizing about what the observation could be are just wrong and not worthy of consideration, he added. Such work can often yield important insights down the road.
"This process of being sure nothing has been missed is going to take longer than discovering something," he said. "Sometimes things at 750 GeV might be relevant for a particle 10 times smaller that hasn't been discovered yet."