November 28, 2021

I, Science

The science magazine of Imperial College

CERN announces discovery of new particle – but is it Higgs?

Earlier this morning, physicists working at the Large Hadron Collider (LHC) in Geneva announced that they had discovered a new particle. At this stage, the characteristics of this particle appear to be in-keeping with what we would expect to observe if it were the famous Higgs boson. At a level of 5 sigma – corresponding to a certainty of 99.9999% – this finding is confident enough to be named a new discovery.

The particle was observed within the mass range expected for the Higgs, 125-126 GeV (125.3 plus or minus 0.6, to be precise –  133 times heavier than the proton) by both ATLAS and CMS experiments. Today’s announcement is based on data collected in 2011 and 2012, with the 2012 data still under analysis.

“The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic,” said Professor Joseph Incandela, elected spokesperson of the CMS experiment at CERN. “This is indeed a new particle.”

A video announcing this morning’s results was accidentally leaked yesterday by CERN, sparking rumours of the existence of Higgs. CERN responded by claiming that they had filmed a video for each eventuality, and that the leaked video was just one of many.

There has been a lot of hype around the Higgs, but with good reason. The standard model of particle physics relies on the existence of the Higgs. Although this result looks promising, all the researchers can claim is to have found an exotic particle lurking within this mass range. Further analysis will reveal whether it displays all the qualities expected of the Higgs boson.