Two University of Washington physicists are among the thousands of physicists who worked to discover a new subatomic particle believed to be the long-sought Higgs boson. The boson is a key part of physicists' model of how the universe works.

When Anna Goussiou and Gordon Watts gathered at a pub in Lower Queen Anne on Tuesday night to hear the latest results of the decades-long search for the Higgs boson, the two University of Washington physicists had a good idea what would be announced. Still, they got a little emotional when they heard the news.

“I have to say I teared up,” Goussiou said.

She and Watts are two of four physicists — along with 10 graduate students and postdoctoral fellows — at the UW who helped make the discovery, which seems to confirm a key aspect of physicists’ model of how the universe works.

Though scientists had predicted the existence of the Higgs boson for half a century, they had not found convincing evidence of its existence until recently. On Wednesday, two teams of physicists announced that they had found a particle that looks an awful lot like the Higgs.

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“It’s like this boogeyman that’s been hanging over us, kind of taunting us,” Watts said.

The Higgs boson — in theory, at least — is a subatomic particle that gives mass to other tiny particles, such as protons. Watts’ favorite analogy is that of a cocktail party. An ordinary person could walk through such a party without attracting attention. But if George Clooney, say, walked through, he would gather a throng of admirers as he went.

Similarly, some particles, such as photons, would pass through the Higgs field without gaining mass. But other particles would gain mass the same way Clooney would attract admirers.

To search for the Higgs boson, scientists smashed protons together in a mammoth particle accelerator called the Large Hadron Collider, near Geneva, Switzerland. When the protons collided hard enough, they produced the new Higgs-like particle for an infinitesimal fraction of a second.

Watts and Goussiou are part of a team of about 3,000 physicists from around the globe who analyzed the data from the collisions. (A second, independent team came up with nearly identical results.)

With so many physicists hunting for the Higgs, Goussiou and Watts each broke off pieces of the larger puzzle to work on.

When the Higgs-like particle decays after its short life span, it can leave behind different types of particles. Goussiou hunted for signs of the new particle decaying into tiny particles called taus, while Watts looked for signs of it decaying into a type of theoretical particle called “hidden valley pions” — so named because they can travel for several meters before becoming visible.

Now that physicists believe they have found the Higgs, the two scientists will continue to examine the ways in which the new particle decays to determine if it behaves as their models predicted.

Watts and Goussiou, who are both 45, have been hunting for the Higgs for more than a decade, but their love of physics goes back much further.

Watts grew up around physics; his father, Terence L. Watts, was a physicist at Rutgers University. Goussiou fell in love with the field in high school in Greece. “I was immediately and totally taken with it,” she said.

Watts said that fascination hasn’t diminished.

“I’m 45 years old and I still pull all-nighters with regular frequency,” he said. The only difference, he added with a laugh, is that now he must take his young daughter to school in the morning.

Asked to describe the significance of Wednesday’s discovery, Watts put it succinctly: “Another big piece of the puzzle that describes the universe we live in has fallen into place.”

Theodoric Meyer: 206-464-2168 or Twitter: @theodoricmeyer.