Born: 18 January 1921, Tokyo, Japan
Died: 5 July 2015, Osaka, Japan
Affiliation at the time of the award: Enrico Fermi Institute, University of Chicago, Chicago, IL, USA
Prize motivation: "for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics"
Field: particle physics
Prize share: 1/2
For a long time, physicists assumed that different types of symmetries characterise nature. In a kind of mirror-world, the physical laws should be the same if right and left are exchanged and if matter is replaced by antimatter. However, symmetries had sometimes been shown to be violated. Yoichiro Nambu formulated in 1960 a mathematical theory for understanding symmetry violations, giving a basis for better understanding the elementary particles and their interactions.