Did scientists at CERN discover a new particle?

The Large Hadron Collider (LHC) restarted operations last spring after two years of upgrades and back in December, the project appeared to yield signs of a new particle that was previously unknown.

“It’s a hint at a possible discovery,” Csaba Csaki, theoretical physicist from Cornell University who isn’t involved in the project, told the Associated Press. “If this is really true, then it would possibly be the most exciting thing that I have seen in particle physics in my career — more exciting than the discovery of the Higgs itself.”

In 2012, physicists were able to confirm the existence of the Higgs boson, referred to as the “God particle”, thanks to LHC experiments. The particle cemented the status of the Standard Model of physics, which strives to clarify how the universe is organized at the smallest level.

Breaking down the Standard Model

In December, the LHC’s Atlas and Compact Muon Solenoid particle detectors spit out initial readings that indicated a particle not included by the Standard Model might exist at 750 Giga electron Volts. This unknown particle would be almost four times more massive than the top quark, the biggest particle in the simulation, and six times bigger than the Higgs, CERN officials said.

The Standard Model has stood up well, but has holes exist, particularly around dark matter, which is thought to make up one-quarter of the mass of the universe. If the initial December results are validated, they could help solve that mystery; or it could indicate a graviton – a theoretical first particle with gravity – or a different boson, even suggest the existence of a new dimension.

More information is needed to resolve those possibilities, and even then, the December outcomes could just be a fluke. However, with so much still unexplained, physicists say discoveries of new particles may be inevitable as colliders get more and more powerful.

“This particle — if it’s real — it would be something totally unexpected that tells us we’re missing something interesting,” said Dave Charlton, who heads up the LHC’s Atlas team

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Image credit: CERN