Summer Abroad students probe the subatomic universe at CERN, the world’s largest particle physics lab

September 7, 2022 by Chris Sasaki - A&S News

In 2012, physicists made headline news around the world with the discovery of the Higgs boson, a lynchpin in the standard model of particle physics, the theory describing all matter and forces in the universe. The breakthrough was long-sought confirmation of the theory explaining why some particles have mass and others do not.

The Nobel Prize-winning discovery was made with the ATLAS and CMS detectors on the Large Hadron Collider (LHC), the most powerful particle accelerator ever built. The LHC is located just outside Geneva, Switzerland, at the European Organization for Nuclear Research — known by its French acronym, CERN – the largest particle physics laboratory in the world.

For years, a team of over thirty physicists from U of T — including students, postdoctoral fellows and faculty — have been leading members of the groundbreaking ATLAS collaboration. The team includes Pekka Sinervo, a professor in the Faculty of Arts & Science’s Department of Physics.

During the summer of 2022, two Arts & Science undergraduate students, supervised by Sinervo, had the opportunity to live in Geneva and conduct research at the LHC thanks to U of T’s Summer Abroad program. The program provides students with opportunities to take courses in international locations where they gain invaluable experience.

Harsh Jaluka is a member of Trinity College and is entering his third year of a math and physics specialist program. Kelvin Leong is a member of New College and is entering his fourth year of an astronomy and physics specialist program.

For Leong, the experience brought him full circle. “My interest in particle physics began ten years ago when the Higgs boson was first discovered,” he says. “It was such big news at the time — that's what got me interested in particle physics in the first place.”

Physicists explore the subatomic realm by smashing particles together using the LHC. They then study what happens in those collisions using detectors like ATLAS and CMS. Typically, such experiments are used to confirm the existence of particles predicted by theory — for example, the Higgs boson. Other experiments measure the characteristics of the collisions and their fallout to see if they match theorists’ predictions.

“It was an incredible opportunity. You get to spend two months working on the LHC, the most complex machine ever built. You get to do research and gain invaluable experience. You get to be in Switzerland, a beautiful country. So really, there were no drawbacks to this program. It was a win-win scenario.”

“I was measuring the frequency of a rare event — the appearance from a collision of a massive particle called a top quark,” says Leong.

Says Jaluka, “I was looking at collisions in which a top quark and a Higgs boson are produced. Not only that, but we were looking for events in which the particles were ‘boosted’ — that is, when they had higher than normal energies and then decayed into other particles called hadrons.”

For Sinervo, the Summer Abroad program pays dividends for him as an instructor and for his students.

“It gives me an opportunity to work with outstanding students who have a strong interest in the physical sciences,” he says. “I enjoy the interaction with them and sharing my own interest and excitement in what we are doing at CERN.

Two men in hardhats inside the ATLAS detector on the Large Hadron Collider
The ATLAS detector on the Large Hadron Collider. Photo: © CERN.

“And the students see how research is done,” he says. “They see there’s a lot of slogging, getting familiar with an experiment, understanding the tools we use — and then applying them to make progress on instrumentation or analysis of data. They also get a taste of what progress looks like in a fundamental research group. This is what physics is all about — not lectures and undergraduate labs!”

For Jaluka, the summer provided valuable career guidance. “When you're studying physics, the question is always whether to go into experimental or theoretical physics,” he says. “So this experience gave me a good idea what experimental physics looks like — what you do on a day-to-day basis. It’s been very helpful in thinking about my future career.”

And when the students weren’t working, they took full advantage of living in Geneva. Jaluka explored the city on bicycle and took in the culture it had to offer. Leong, who had never been to Europe before, visited Bern, Lyon and other destinations.

“It was an amazing experience,” Leong says. “Working there really made me feel like I was contributing to physics research.”

“It was an incredible opportunity,” echoes Jaluka. “You get to spend two months working on the LHC, the most complex machine ever built. You get to do research and gain invaluable experience. You get to be in Switzerland, a beautiful country. So really, there were no drawbacks to this program. It was a win-win scenario.”

Learn more about all the international opportunities available to Arts & Science students, including Summer Abroad experiences across the globe — which allow students to complete one full-year course in three to six weeks. Location sites include Asia, Europe, Australia and the Americas.