Scientists are trying to work out if a strange new particle, dubbed a “ghost particle”, has been detected at CERN’s Large Hadron Collider (LHC) in Switzerland.

Using the Compact Muon Solenoid (CMS) instrument on the particle accelerator, the team said they had seen a signal that could be a particle that’s twice the mᴀss of a carbon atom. But as the particle does not fit known theories, it could cause a bit of a stir if it exists. Their findings, which have not yet been peer-reviewed, are available on arXiv.

“I’d say theorists are excited and experimentalists are very skeptical,” Alexandre Nikitenko, a theorist on the CMS team who worked on the data, told The Guardian. “As a physicist I must be very critical, but as the author of this analysis I must have some optimism too.”

The team were due to discuss their findings in a meeting today at CERN. Those findings suggest a build-up of muons, which are heavy electrons, in the CMS detector. This would correspond to a particle with a mᴀss of 28GeV, which is about a quarter the mᴀss of the Higgs boson at 125 GeV.

It may take another year to find out if this particle is real or not, but as Science Alert notes, even if it is real it’s not exactly physics-breaking. “But it is strange – a mᴀss that has formed where no mᴀss was expected,” they said.

This isn’t the only particle news we’ve had this year. In fact, this isn’t even the only “ghost particle” news we’ve had, because in July, astronomers announced the discovery of neutrinos coming from an energetic galaxy 4 billion light-years away – a slightly different discovery, for sure though.

Perhaps more relevant was the news from September this year, when scientists suggested they “broke the Standard Model” with the detection of ultra-high energy cosmic neutrinos using the Antarctic Impulsive Transient Antenna (ANITA).

In March, there was news of the weirdly named “skyrimon”, a particle with ball lightning-like properties. And also in September, results at CERN hinted at a particle that seemed to defy the Standard Model.

Will this latest discovery stand up to scrutiny? Time will tell. But it’s certainly an exciting time for physics at the moment.