University of Guelph scientists are part of a team of Canadian and international researchers whose studies have won a Nobel Prize in Physics.

The announcement was made today by the Royal Swedish Academy of Sciences.

The Nobel Prize is shared by Art McDonald, a physics professor at Queen’s University who directed the Sudbury Neutrino Observatory (SNO) in the 1990s and Takaaki Kajita, head of the Super-Kamiokande Collaboration based at the University of Tokyo.

Data collected and analyzed by U of G physicists at SNO helped establish that neutrinos have mass.

The Guelph team consisted of professors emeriti Jimmy Law, Robin Ollerhead, and Bernhard Nickel; retired professor John Simpson; researchers Pillalamarr Jagam, Diane Reitzner and Jian Xiong Wang; and PhD students Tom Andersen, Marc Bergevin, Myung Chol Chon and Nathaniel Tagg.

Neutrinos like those generated by the sun are among nature’s most elusive particles. The SNO lab detected their presence and showed, contrary to what many scientists believed, that these particles have mass.

“It turned out that the initial assumption dating from 1930 that the neutrino was massless didn’t work,” said Law.

SNO is a unique neutrino telescope that is the size of a 10-storey building. It’s located two kilometres beneath the earth in a nickel mine near Sudbury, making it the world’s deepest underground laboratory.

SNO is the only facility in the world that can detect neutrinos accurately, thanks to the giant sphere filled with ultra-pure heavy water that contains heavy hydrogen. Neutrinos passing through break up the deuterium into a neutron and a proton, which is crucial to the measurement process.

Guelph scientists were part of the original group helping with research and development and the construction of the SNO detector. They also helped in design, construction and operation of SNO’s sophisticated instruments and in analysis of data.