Nobel Prize in Physics awarded to Arthur B. McDonald

October 6, 2015

Credit: K. MacFarlane. Queen's University

OTTAWA, ONTARIO — The Canada Foundation for Innovation (CFI) congratulates Arthur B. McDonald, a particle physicist and professor emeritus at Queen’s University in Kingston, Ont., who has been named the co-winner of the 2015 Nobel Prize in Physics. The award, announced by the Royal Swedish Academy of Sciences today, will be shared by Japan’s Takaaki Kajita, a physicist at the University of Tokyo.

The Academy recognized the researchers for their discovery of the nature of neutrinos, some of the smallest and most abundant particles of matter in the universe. For years, these subatomic particles were considered to have no mass, a notion that supported the standard model of particle physics. However, in separate observations made in 1998 and 2001, Kajita and McDonald noticed neutrinos changed in ways that required them to have mass, even if this mass was remarkably small.

McDonald made his observations at the Sudbury Neutrino Observatory (SNO), now commonly known as SNOLAB. The particle physics facility is located two kilometres below the Earth’s surface in a nickel mine in Sudbury, Ont. It is the second deepest underground facility in the world. Since 2002, the SNOLAB has received funding through the CFI, most recently through the 2015 Innovation Fund.

McDonald’s discovery, combined with the similar conclusions made by Kajita in Japan’s Super-Kamiokande detector, have inspired particle physicists around the world to investigate the properties of neutrinos, along with other subatomic particles. Their observations have dramatically altered our understanding of the origin and behaviour of matter in the universe.