Originally published July 4, 2012 at 10:22 a.m., updated July 4, 2012 at 3:28 p.m.
James Branson, Physicist and UCSD Professor.
Explanations of the Higgs boson:
NPR's Q&A with science blogger and astrophysicist Adam Frank.
Radiolab's co-host Robert Krulwich explains Higgs before the big announcement.
Guardian science correspondent Ian Sample explains the Higgs boson using sugar and ping pong balls.
Four physicists from UC San Diego worked as part of the team that discovered what they think is the Higgs boson, a new subatomic particle nicknamed the “God particle” because it gives everything its mass.
If the discovery is indeed the Higgs boson, it could provide key explanations of why particles like electrons have mass, or substance. Scientists said the Higgs is the missing link in a theory that explains the basic nature of the universe.
Evidence of the Higgs boson particle would help prove the existence of a field that spreads through the universe. When other particles cross this field, called the Higgs field, they are given mass. So the Higgs field would explain why every object on Earth actually has substance—why we can’t walk through walls or pass our hands through tables.
Scientists have long believed this field existed, but they haven’t found direct proof. This discovery could provide that proof.
James Branson, one of the UCSD physicists who worked on the project, spoke to KPBS just after returning from the site of the discovery at European Organization for Nuclear Research, or CERN's particle accelerator in Geneva, Switzerland.
“It changed the universe,” he said about the Higgs particle. “The Big Bang came, we had all these massless particles, there was this phase transition, where this Higgs field coalesced and made this background field that everything else has to plow through and gave everything mass.
“So basically the character of the whole universe changed when this happened.”
Branson said at the beginning of the universe, before the Higgs field existed, particles had no mass.
“So they were all flying around at the speed of light, bouncing around off each other a little bit, but you couldn’t really coalesce anything,” Branson said.
A trillionth of a second after the Big Bang, scientists believe the Higgs field was created.
“Once the Higgs transition came, we got mass and could make elements and chemicals and stars and things like that,” Branson said.
Finding evidence of the Higgs is extremely difficult. To create it, scientists slam protons together in a circular tube called a particle accelerator. This tube, the Large Hadron Collider, is more than 500 feet below ground and is so long—its circumference is 17 miles—that it stretches beneath two countries. The energy from the protons’ collisions creates the Higgs.
But once the Higgs is created, it only exists for a billionth of a billionth of a billionth of a second. So to observe it, scientists look for slight alterations in their measurements that showed it existed and then decayed.
Branson said they essentially take sophisticated photographs every 50 nanoseconds and then examine their photos for evidence of the Higgs.
The particle is named after British physicist Peter Higgs, who helped write a paper published in 1964 theorizing the existence of the Higgs field and its role in creating mass.
In 1993, author Leon Lederman coined Higgs' “God particle” nickname with his popular science book on particle physics, “The God Particle: If the Universe Is the Answer, What Is the Question?”
But Branson said he wishes Lederman had chosen a different name.
“I’m not happy it’s been nicknamed ‘God particle,’” Branson said. “Most of us aren’t.”