Large Hadron Collider data hints at possible new particle discovery

A particle colliderused in the Nobel-prize-winningdiscovery ofthe Higgs boson may have found a hint of a completely new particle at uncharted energies. Or it may just be a "statistical fluctuation."

A suspicious bump that could potentially indicate a new particle being produced and decaying has been detected in data collected by the ATLAS experiment at the Large Hadron Collider(LHC)at CERN, the European organization for nuclear research, CERN said in a news relasethis week.

A bump has also been detected at very similar energies by a completely separate experiment called the CMS experiment, researchers announced at the unveiling of preliminary results collected since the proton-smasher restarted at a higher energy earlier this year after a two-yearshutdown.

We have no idea what it is,if it's real.-Peter Krieger, ATLAS Canada

"Interest has arisen because both experiments see a similar fluctuation," CERN acknowledged in a statement.

However, CERN cautioned,"with each experiment studying hundreds of distributions of this nature, the most probable explanation is coincidence" and the researchers are exercising care in not over-interpreting the result.

• Pentaquarks, new subatomic particles, found at Large Hadron Collider
• New subatomic particles predicted by Canadians found at CERN

More data is needed to tell if the bumps are real or just a "statistical fluctuation."

"Statistically, you'll always find a bump somewhere," says Peter Krieger, spokesperson for the Canadian researchers working on ATLAS and a physics professor at the University of Toronto.

"Hints" of the Higgs boson, which won the Nobel Prize in Physics in 2013, were first announced as bumps seen by both ATLAS and CMS at similar energies.

But at that time, Krieger said, "certainly, we had more data than we have now."

More massive particles now discoverable

He noted that the LHC just started collecting significant amounts of data in June or July.

The LHC was just restarted in March at a new, higher energy of 13 TeV, up from 8 TeV.

The Higgs boson was discovered at a lower energy, but a higher energy will allow physicists to discover more massive particles.

The Higgs boson was the last undiscovered particle predicted by the Standard Model of Physics, which describes the fundamental laws of physics. That model is expectedto break down at higher energies, and physicists aren't sure what they might find next.

The most popular theory predicting particles detectable at higher energies is called supersymmetry, Krieger said. So far, no particle predicted by that theory has ever been found.

Supersymmetry also does not predict a particle at the energy where the new bump was found.

For now, Krieger said, "We have no idea what it is, if it's real."

Whether it's real or not is expected to become clearer next year after more data is collected.

In the meantime, the data collected so far have narrowed the ranges of masses at which physicists expect to find new particles predicted by supersymmetry.