Governor General's Gold Medal
Particle pursuits lead to gold medal

Trying to understand nature at its most fundamental level takes some of the world's biggest scientific instruments. Dr. Brigitte Vachon — Governor General's gold medal winner for her outstanding grade point average and dissertation-put the 27-km CERN particle accelerator in Geneva to the test in her study of what happens when electrons and positrons collide at the speed of light.

The results of her experiment-published in one of the premier particle physics journals, Physics Letters, and presented at several international conferences-have helped scientists set a framework for their pursuit of a better explanation of how the universe formed.

"The so-called 'standard model' is good at predicting nature. It works well with given parameters, such as the mass of an electron. But it can't explain why the electron has the mass it does," Vachon explained over the phone from Fermilab near Chicago, the world's leading particle physics facility, where she's on a three-year post doctoral fellowship.

While her study did not turn up evidence of undiscovered particles that would help to improve the standard model-or lead to an entirely new theory-her results rank as the most precise particle analysis yet recorded.

"Like any science, it's a matter of taking small steps," says Vachon, who grew up in Quebec and hopes to come back to a Canadian university to teach and continue her research.

Apart from doing her science, Vachon is excited about talking about it-whether explaining particle physics to high school students and undergrads, or friends and family.

"It's absolutely incredible when you think about it. Day to day in the lab, we don't think twice about it - 'colliding particles at the speed of light, big deal'-but when you talk to other people it makes you realize that what we do is really cool.

"The significance of our work is always challenging to express, if you're only used to seeing direct implications. We do fundamental research and the only goal is to understand nature. That's the reason we do it. In the course of our research other applications may be developed (the World Wide Web was created at CERN). But we want to know where we came from and where we're going ... it's basic curiosity."

Photo courtesy Fermi National Accelerator Laboratory.