KSU professors at forefront of antimatter discovery

Mark Haymond

One of Discover Magazine’s top twenty science stories of 2011 has roots here at Kent State.

Kent State physics professors Declan Keane and Spyridon Margetis played major roles in discovering the antimatter twin of the gas helium, called antihelium.

Don’t let the name fool you: Antihelium is a heavyweight. Presently, it is the heaviest stable form of antimatter yet discovered, a record that Keane believes will hold up for a long time.

Keane and Margetis were both principle investigators on the project. Aihong Tang, who earned a doctorate from Kent in 2002, developed the software they used to detect the molecule. Keane was the first researcher to present the results at a conference.

The world is full of matter. Antimatter is another story.

“Antimatter is a very exotic form of matter,” Keane said.

Antimatter is far less stable than regular matter, and is destroyed if it comes into contact with regular matter, which makes it very illusive for researchers.

Don’t confuse antihelium with the stuff that makes people’s voices sound funny at birthday parties. This stuff is rare and hard to detect.

“It isn’t looking for a needle in a haystack, but a needle in many haystacks,” Margetis said.

“We had to search through half a trillion particles coming out of these collisions to find the eighteen or so antihelium we discovered,” Keane said.

The discovery was made using the Relativistic Heavy Ion Collider at Brookhaven National Laboratory on Long Island in New York. The RHIC is a particle collider, a two-and-a-half-mile long loop of vacuum tube that accelerates particles to ridiculous speeds and measures the results when they crash into other particles. Technical jargon aside, think of it as the Big Bang in a box.

“The only way we know of to produce antimatter is to create it out of pure energy,” Keane said. “Einstein’s famous formula tells us that you can convert matter into energy, and the opposite is also true. If you have particles colliding together with a lot of energy, out of that energy you can create new forms of matter.”

Imagine a kid smashing his Matchbox cars together on a plastic racetrack. Now imagine that the plastic track is over two miles long and the toys are atoms of gold traveling near the speed of light.

Particle colliders replicate the conditions that existed less then a millisecond after the Big Bang, when all of the matter and energy in the universe was concentrated in a very small space.

Keane said during this explosive moment matter and antimatter existed in equal parts.

“One of the great mysteries of science is what happened to the antimatter,” Keane said.

Margetis said the research could affect the future of physics, but he said it depends on what they can learn about the structure of the new molecule. Margetis put his hand on a physics textbook to illustrate his point.

“We may end up having to change what’s in here,” he said.

Contact Mark Haymond at [email protected].