Why the Higgs boson announcement is so important (+video)

All the hubbub was due to the fact that the discovery of the Higgs boson is the last piece of the puzzle needed to complete the so-called Standard Model of particle physics — the big picture that describes the subatomic particles that make up everything in the universe, and the forces that work between them.

Over the course of the 20th century, as physicists learned more about the Standard Model, they struggled to answer one very basic question: Why does matter exist?

Higgs and others came up with a possible explanation: that particles gain mass by traveling through an energy field. One way to think about it is that the field sticks to the particles, slowing them down and imparting mass.

That energy field came to be known as the Higgs field. The particle associated with the field was dubbed the Higgs boson.

Higgs published his theory in 1964. In the 48 years since, physicists have eagerly chased the Higgs boson. Finding it would provide the experimental confirmation they needed to show that their current understanding of the Standard Model was correct.

On the other hand, ruling it out would mean a return to the drawing board to look for an alternative Higgs particle, or several alternative Higgs particles, or perhaps to rethink the Standard Model from the bottom up.

Either outcome would be monumental, scientists said.

But the search hasn’t been easy. To create exotic subatomic particles for study, physicists use huge colliders to smash bits of atoms together. CERN built its $10 billion Large Hadron Collider in large part to produce a particle as massive as the Higgs boson was expected to be; no other collider in the world was up to the task.

The LHC, as it’s known, shoots beams of protons around a 17-mile circular track underground — accelerating them nearly to the speed of light and crashing them together to create bursts of subatomic particles.

Scientists on the two research teams — known as CMS and ATLAS — use two different detectors to analyze the patterns formed by the particles. If a Higgs boson were to be created, it would decay immediately into one of several combinations of other particles, theorists have suggested. These combinations are what scientists search for in the 800 trillion proton-proton collisions recorded at the LHC.

In December, CERN announced that both teams had uncovered “tantalizing hints” of a Higgs boson with a mass of about 125 billion electron volts.

Physicists said they didn’t expect Wednesday’s announcement to come so soon, and that the collider’s performance had exceeded all expectations.

“I am astounded at the amazing speed with which these results have emerged,” Higgs said in a statement. “I never expected this to happen in my lifetime.”

John Gunion, a theoretical physicist at the University of California, Davis and co-author of a book called “The Higgs Hunter’s Guide,” said he was satisfied that the new particle was associated with the production of mass in the universe in the moments after the Big Bang.

The next step, he and others said, would be to figure out whether the particle is indeed the single Higgs boson described by the Standard Model or some exotic variant. Proponents of a theory known as supersymmetry, for instance, believe that there are multiple Higgs bosons.

“There’s plenty of room for surprising details,” said Wilczek, a supersymmetry fan.

In the meantime, physicists at CERN won’t get much of a chance to enjoy their party.

Cousins said that he was already doing mop-up work, putting together documentation that normally would have appeared at the same time as the seminar. Many of his CERN colleagues hopped on planes to attend the conference in Melbourne.

Others will keep their eyes on their computer screens and continue studying collisions. The next phase of data collection for the Higgs search, which had been scheduled to wrap up in October, will now run into December, Sharma said. That should give CERN scientists three times more collisions to study than the 800 trillion they’ve already amassed.

“We are in hot pursuit,” he said. “You push it as much as you can.”

But even that won’t be enough to reveal definitively the true nature of the new particle, he added.

After December, the LHC will go dark for two years while its equipment gets an upgrade. Then it will pick up the search where it left off.

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