Precision wins physics professor a lifetime achievement medal


TORONTO, Nov. 13, 2020 – Precision matters. York University Distinguished Research Professor Eric Hessels, who has conducted the most precise measurement to date of the fine structure of helium and of the hydrogen n=2 Lamb shift to come closest to solving the proton-size puzzle, deals in precision every day. It is his work in the precision measurement field that has earned him the 2020 Canadian Association of Physicists (CAP) Medal for Lifetime Achievement in Physics.

It is the first time in the association’s history, since the award began in 1956, that it has gone to a York Department of Physics and Astronomy professor. The annual medal awards researchers for their distinguished service to physics over an extended time or a recent outstanding achievement. Hessels fits both categories.

“We could not be more delighted or more proud that Dr. Hessels will receive this prestigious honour for his lifetime of dedication to research in physics,” said Faculty of Science Dean Rui Wang. “Dr. Hessels’ work has far-reaching consequences for our understanding of the laws of physics and may help answer some of the unresolved fundamental questions of the Universe. His impact at York University and within our faculty has been enormous, as is the imprint his research will leave on the discipline of physics.”

York University Distinguished Research Professor Eric Hessels in his lab

York University Distinguished Research Professor Eric Hessels receives the 2020 CAP Medal for Lifetime Achievement in Physics. Photo by Paola Scattolon

Hessels, renowned for his work in atomic, molecular and optical physics, is a master at developing novel and sophisticated laser and microwave experiments to ascertain the properties of atoms and nuclei, such as the dual charge exchange method and the frequency offset separated oscillatory fields (FOSOF) technique. The first method made antihydrogen atoms cold enough to trap and study, while the FOSOF technique was used to measure the radius of a proton.

“Professor Hessels specializes in precision measurement to test fundamental theories of physics. His work is important in advancing our understanding of nature and how it works,” says Patrick Hall, chair of the Department of Physics and Astronomy. "His research group provides invaluable opportunities for graduate and undergraduate students and postdoctoral fellows at York to be involved in cutting-edge science."

His most recent research involves measuring the electron electric dipole moment using polar molecules frozen into a cryogenic argon solid, which could help explain why there is an abundance of matter, but very little anti-matter in our Universe. He is leading a collaboration of 19 physicists and chemists working on this measurement.

“I am very honoured to receive this award,” says Hessels. “I would like to acknowledge the hard work and intelligence of my students and collaborators, as the work being honoured here would not have been possible without them.”

A professor at York since 1992, Hessels has won several prestigious awards over the years, including The John Charles Polanyi Prize, the Herzberg Medal, and the U.S. National Institute of Standards, Technology Precision Measurements Award and two Canada Research Chairs.

Hessels will deliver a plenary medal talk in the coming months, which will be posted to the CAP website.


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