“As a layman, I would now say, I think we have it,” said CERN director-general Rolf-Dieter Heuer. “It’s a historic milestone today. I think we can all be proud, all be happy.” Both CMS and ATLAS, the two main LHC Higgs-hunting experiments, are reporting a boson that has Higgs-like properties at a mass of 125 gigaelectronvolts (GeV) with a 5-sigma significance, meaning they are 99.999 percent confident of its existence.
At the first mention of 5-sigma by physicist Joe Incandela, who presented results from one of the main Higgs-searching efforts at the LHC, the audience burst into applause. “It was really a magnificent moment to see the reaction from the community,” he said later in a question and answer session. “Emotionally it didn’t really hit me until today because we have had to be so focused, and so much work to do.”
Though CERN scientists are making sure to be cautious about over-interpreting their data, the results are impressive and historic, and today will likely go down as the day the Higgs discovery was announced.
“This boson is a very profound thing that we have found. This is not like other ordinary particles,” Incandela said. “We are reaching into the fabric of the universe like we’ve never done before. It’s a key to the structure of the universe.”