Christopher Hearty

University of British Columbia

A 75-year-old treasure hunt is still alive and well at TRIUMF, Canada’s National Laboratory for Particle and Nuclear Physics in Vancouver.

The fortune being pursued? Anti-matter – material composed of anti-particles, which are like ordinary protons, electrons and neutrons except they have opposite electrical charges and magnetic movements.

Some call anti-matter the “mirror of the universe” for its opposing characteristics to that of matter.

“If you look around, everything we see in the universe is made of matter,” says Christopher Hearty, an associate professor with University of British Columbia’s Department of Physics and Astronomy. “It’s not made of anti-matter so it’s clear there is some difference in the laws of physics just by the fact that the universe is made up entirely of matter, not antimatter.”

Since 1930, researchers have been searching for and attempting to understand anti-matter. Today anti-matter can be created in a laboratory, using high-powered accelerators and detectors. An example of that is the BaBar experiment, one of the largest active collaborations in the world.

“The main goal of BaBar, the reason the experiment has gone ahead, is to understand the difference in the laws of physics between matter and anti-matter,” says Hearty, one of nearly 600 scientists involved in the project.

Located in California, BaBar is a collaboration of researchers from 73 institutions and 19 different countries. BaBar’s Canadian contingent includes nine faculty members hailing from the University of British Columbia, the University of Victoria, the University of Montreal and McGill University.

Hearty, the physics analysis coordinator for BaBar, is currently based at the Stanford Linear Accelerator Center (SLAC) in California for the project. He will return to University of British Columbia in August 2005

“The point is not to try and develop uses of anti-matter but rather the goal is to understand the basic laws of physics that govern our universe,” Hearty says.

Although the manpower Canada brings to BaBar represents only a small percentage of the participants in the project, Hearty notes what we lack in numbers we make up with in resources.

“What we do have is good computing facilities so we’ve been producing roughly 25 per cent of the simulated data for the project,” he says. “We’ve been able to have a big impact on the collaboration through our use of CFIfunded facilities to reach far beyond our actual size of manpower.”

Hearty’s work with BaBar involves producing B-mesons (a particle nearly five times the mass of a proton) and their anti-matter equivalent, anti-B-mesons, and looking for differences in their properties.

“I like the basic research. I like looking to discover new things at the really basic level and laws of physics,” Hearty says. “Also, we have these very large collaborations and large facilities, I enjoy that working environment.”

His project reached its first major milestone about two years ago. Researchers saw the first solid evidence of charge-parity (CP) violation in their studies. CP is a symmetry that relates matter to anti-matter. Given that the observed universe is made of matter, it is clear that CP is violated, Hearty says.

The data Hearty’s team is collecting contains hints that the amount of CP violation in B-mesons using different decay methods is different than what is expected in the Standard Model – the current theory of fundamental particles and how they interact.

“I would go so far as saying that if this is confirmed by further measurements over the next year and a half this would be the first evidence for physics beyond the Standard Model, period,” Hearty says. “I think this would be a major discovery if this actually does continue in the direction it’s going.”

The Standard Model has been a successful template so far, but Hearty notes it is not the final model for everything.

“I think we all believe there is something missing from the Standard Model. There has to be some other new physics that we just haven’t seen yet,” he says. “It wouldn’t be shocking to people to find new physics, because I think people believe or hope that there is physics we don’t know about yet. Nobody knows what the new physics is but they know there has to be something.”