CERN researchers are investigating the potential presence of a new, unexpected “ghost particle” which may have appeared during Large Hadron Collider (LHC) experiments.
Unexplained “bumps” appeared in data produced by the team’s multipurpose Compact Muon Solenoid (CMS) detector, which may show traces of an as yet unidentified ghost particle around twice the size of a carbon atom. Two separate analyses of the data indicated a build-up of muons, or heavy electrons, in the detector – if the data is accurate, it indicates a new particle with a mass of 28GeV, around a quarter of the mass of a Higgs Boson particle.
The data bumps were more pronounced during low energy collisions than the more energetic collisions which took place after the LHC underwent an upgrade. It has been theorised this is due to the higher level of background particles produced by high energy collisions.
The CMS team will continue to investigate further the possibility of the ghost particle, which could take around a year to fully ascertain; and the CERN team working on the LHC’s other multipurpose detector, Atlas, is cross-checking its own data for similar bumps. CMS theorist Alexandre Nikitenko said: “If it is confirmed by Atlas it will be the real thing. It will be really something terribly new.”
Data results collected by Aleph, a detector on the LHC’s predecessor the Large Electron-Positron Collider, have been re-analysed in an attempt to detect further signs of the ghost particle. A bump at 30GeV, similar to the new findings, was discovered.
If additional evidence is found to indicate the presence of the ghost particle, theorists say it will not fit into present models. The data may yet be found to be anomalous, CERN researcher Michelangelo Mangano cautioned: “it is a bit early to get excited. Given that Atlas has yet to release their analysis, and given that much more data is on tape even for CMS, it is clear that the effect will soon be confirmed or diluted away.”