Scientists have announced the discovery of an entirely new kind of particle that is almost certainly the long-sought “God particle,” the Higgs boson.
The European Organization for Nuclear Research (CERN), the international scientific agency that had been leading the hunt for the particle, made the announcement of a new particle “consistent” with the Higgs boson on early Wednesday in Geneva.
“We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer in a statement. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”
The Higgs boson is the last missing piece scientists needed to explain how all matter in the universe has mass under the Standard Model, the most-widely accepted theory of particle physics.
The finding comes after weeks of speculation and rumor, even an accidental leak of information ahead of the announcement when CERN posted a press video on Tuesday.
CERN scientists wrapped up three months of proton collision experiments performed at nearly the speed of light using the Large Hadron Collider, the world’s largest and most powerful particle accelerator, a 17-mile-around ring located underground by CERN’s headquarters near Geneva, Switzerland.
It was in the minuscule debris produced by these collisions, which last for only fractions of a second before decaying into more stable known particles, that scientists were able to find traces of the particle which they believe is Higgs.
CERN published the following video of one of the collisions that may have produced the Higgs particle.
While CERN confirmed it definitely found a new type of particle, the agency must conduct further analyses of its properties to be sure that the particle is unquestionably the Higgs boson.
But all initial indications fit with what is expected of the Higgs, particularly the particle’s mass, which is the heaviest ever recorded of any boson — 126.5 gigaelectronvolts (GeV), which is about the mass of an entire atom of iodine, made up of other particles. In comparison, an electron has a mass of 0.000511 gigaelectronvolts.
Two separate experiments running on two giant pieces of equipment along the collider were behind the discovery, called ATLAS and CMS, respectively.
The CMS experiment observed the new type of particle around 125 gigaelectronvolts with a 5 sigma signal. The higher the sigma signal, the less likely the results are to have occurred by chance.
The ATLAS experiment, by contrast, observed the new particle around 126 gigaelectronvolts, also with a 5 sigma signal.
But thousands of scientists around the globe were involved in studying the data collected by both experiments. And the latest results were combined with those recorded by the experiments in 2010 and 2011 to be able to locate the new particle amongst the hundreds of billions of debris.
“Courtesy to our staff, without whom we would not be where we are today,” said Heuer during a press conference after the announcement acknowledging that not all of the scientists who deserved credit for the new particle’s discovery could fit in the auditorium.
“This is an incredible, exciting moment,” added Maria Spiropulu, a physics professor at Caltech, in a statement. “Even these early results give us important hints as to how mass in the universe came to be. Together with hundreds of our colleagues, we have worked for decades to reach this point.”
The Higgs boson was first predicted in the 1960s by several scientists, including British theoretical physicist Peter Higgs, for whom it is named. But the particle has never before been observed by humanity until now.
Editor’s note: Updated to add comparisons of the new particle’s mass and background on the weeks leading up to the discovery.
