Born: 9 March 1959, Higashimatsuyama, Japan
Affiliation at the time of the award: University of Tokyo, Kashiwa, Japan
Prize motivation: "for the discovery of neutrino oscillations, which shows that neutrinos have mass"
Prize share: 1/2
The Standard Model used by modern physics has three types of a very small and elusive particle called the neutrino. In the Super-Kamiokande detector, an experimental facility in a mine in Japan in 1998, Takaaki Kajita detected neutrinos created in reactions between cosmic rays and the Earth's atmosphere. Measurements showed deviations, which were explained by the neutrinos switching between the different types. This means that they must have mass. The Standard Model, however, is based on neutrinos lacking mass and the model must be revised.