Two high-energy photons (red towers) resulting from a proton-proton collision. This is what scientists expect to see from the decay of a Higgs boson. Photo: CERN 2012

Result Opens New Doors

Higgs Sighting Reported at CERN

Thousands of physicists conducting research at the European Organization for Nuclear Research, or CERN, have announced observation of a new particle with a mass consistent with the predicted Higgs particle. If confirmed, the discovery may one day lead to an understanding of how visible matter gets its mass.

Two collaborations of scientists, the ATLAS and CMS experiments, analyzed data from the collisions of trillions of protons with other protons in the Large Hadron Collider at CERN, which straddles the border between Switzerland and France near Geneva. A preliminary analysis of the data from both experiments yielded hints of a new particle with mass 125-126 GeV.

"The discovery of the Higgs has been a long time coming and is an important science milestone. I hope that, as do many others, it is the gateway to a new layer of understanding of our universe. On behalf of everyone at Jefferson Lab: Congratulations to all involved!" said Jefferson Lab Director Hugh Montgomery.

This range is consistent with the recent announcement by two groups of experimentalists who took data at Fermilab's Tevatron. There, hundreds of physicists in the CDF and DZero collaborations analyzed more than 500 trillion collisions of protons in data taken over about a decade of research, from 2001 until the Tevatron was shut down in September 2011. Those results indicated that the Higgs particle would have a mass between 115 and 135 GeV.

The CERN data were taken in 2011 and 2012, and the ATLAS and CMS collaborations stress that the full analysis of data from these experiment is not yet complete. The collaborations anticipate that a more precise measurement of the new particle will be unveiled in an announcement later this year, after the experiments have more data. The CERN data are much more powerful statistically. Chances of less than one in millions are quoted for the apparent signal being a background fluctuation, and the mass value is considerably narrowed.

Further exploration of its characteristics will be needed to determine its significance, including its positive identification as the long-sought Higgs, the nature of its interactions with other subatomic particles, whether it obeys the Standard Model of particle physics, or whether it is a completely unexpected addition to the particle zoo. No matter the final result, this observation will be an important addition to our knowledge of the universe.

"This result is certainly a great achievement for physics, and provides strong support for the Standard Model of particles and interactions. The remaining challenge is to continue to search for the new physics needed to explain dark matter and energy, as well as the reason for the observed Higgs mass. This work will involve additional LHC running at the energy frontier, but also precision tests of the Standard Model at lower energies. Such precision tests are an important part of the experimental program at Jefferson Lab, as well as other facilities around the world," said Jefferson Lab Scientific Director Bob McKeown.

If identified as the Higgs particle, further exploration could yield deep insight into our universe. The Higgs boson is part of a theory that describes the Higgs field. The Higgs field interacts with subatomic particles through the Higgs boson, and this interaction is what is thought to imbue those particles with mass.