Physics community waits for proof of a particle’s existence

Two Kent State physics professors are involved with an experiment set to run on the Large Hadron Collider, the world’s largest particle accelerator.

The Large Hadron Collider, or LHC, is 17 miles in circumference and 570 feet underneath Geneva, Switzerland. On Sept. 19 last year, the LHC was taken offline because of a faulty electrical connection with one of the 1,600 27-ton magnets. It returned online about two weeks ago.

Spyridon Margetis, physics professor and director for Kent State’s Center of Nuclear Research, said he and his colleague, physics professor Declan Keane, are unofficially part of A Large Ion Collider Experiment, also known as ALICE. The experiment includes about 2,000 people from around the world working toward finding out what matter was like within the first second of the Big Bang, he said.

“We all talk about mass. This thing, it appears heavy, it has a mass,” Margetis said. “If I try to push it and accelerate it, it has a resistance. That resistance, the inertia, we call it mass. We have experience with mass, but we don’t really know what it is.”

Margetis said it is theorized that after the Big Bang, matter formed from a hot mix of particles. Matter is made of atoms, which are made of protons and neutrons. Protons and neutrons are made of quarks, and quarks are held together by other particles called gluons.

In the very early stages of the universe, he said, it would have been too hot for gluons to hold quarks together. Instead, they were mixed together in what is called quark-gluon plasma. The goal of ALICE is to create conditions like those just after the Big Bang to study the quark-gluon plasma.

“So there is a theory that actually explains how this mass was acquired,” Margetis said. “But physics is an experimental science. Unless we verify things by experiment and testing, nothing is accepted officially.”

Thomas Emmons, a physics professor who teaches Seven Ideas that Shook the Universe, said another experiment planned for the LHC is to find what’s called the Higgs boson particle. He said the particle is made of four forces – the strong nuclear force, weak nuclear force, electromagnetic force and gravity.

“Imagine you’re walking through mud,” Emmons said. “The Higgs particle kind of makes this mud. It’s called a Higgs field. The Higgs particle is supposed to make this mud, and without it, you couldn’t have matter.”

Emmons said it is a large particle in terms of physics, and the larger a particle is, the faster it will break apart. He said if the LHC manages to create this particle, it will break apart within a millionth of a billionth of a billionth of a second.

“That’s such a short time that nobody could measure it or see it,” Emmons said. “But when the Higgs particle breaks apart, they’re going to look at the pieces. That’s how they’ll actually discover it.”

Emmons said physicists are almost convinced they will find the particle. However, if they don’t find it, he said, it will really upset the physics community.

“We are more or less sure it is there, but we have to have proof,” Margetis said. “This is the major thing for LHC, the discovery of the Higgs boson particle, the undisputed proof that this thing exists. Otherwise, back to the blackboard.”

Contact technology reporter Allison Smith at [email protected].