York researcher and a team of scientists uncover a clue in antimatter mystery

A York University professor and a team of researchers have uncovered an important clue in one of the great mysteries of science: What happened to the antimatter that was created at the birth of the universe?

Wendy Taylor (right), York’s Canada Research Chair in Experimental Particle Physics, is among a group of a dozen researchers from around the globe who have directly determined, for the first time, the frequency at which a rare particle spontaneously transforms from matter to antimatter and back.

The group of scientists found that a subatomic particle, the B_s meson, transforms, or “oscillates” between matter and antimatter at a rate of more than 17 trillion times per second – one of nature’s fastest rapid-fire processes.

The measurement, conducted at Fermilab, the US Department of Energy’s Fermi National Accelerator Laboratory, is the culmination of more than five years of research by members of the B_s Mixing group of the DZero collider detector collaboration.

Scientists have hoped that the spontaneous transition of the B_s meson into its own antiparticle could yield clues as to what happened to the antimatter scientists theorize was created during the Big Bang, and why our universe was apparently left composed of matter only. Researchers have coined this paradox “matter-antimatter asymmetry.”

“The theory is that matter and antimatter should have both been annihilated into pure energy at the birth of the universe,” says Taylor. “Clearly this did not happen. The big question is of course, ‘why?’ This finding is certainly an important piece of that puzzle.”

She says that researchers had hoped the frequency of the oscillations would turn out to be much higher, which would indicate new physical processes that could explain the antimatter mystery.

“So far, we have a result that is very interesting and unique in terms of particle physics research, but no answer to the problem of matter-antimatter asymmetry. But that’s the joy of science. It just means that particle physicists still have a lot of important work to do.”

Taylor’s role involved several aspects of the measurement of these particle oscillations, particularly with regards to the level of precision of the experiment and developing techniques to account for the particles that could not be observed in the DZero detector.

The paper, “First Direct Two-Sided Bound on the B_s^0 Oscillation Frequency” has been submitted to the journal Physical Review Letters.