Takaaki Kajita

Takaaki Kajita
Takaaki Kajita, Nobel Laureate in physics in Stockholm December 2015
Native name	梶田 隆章
Born	(1959-03-09) 9 March 1959 (age 57) Higashimatsuyama, Saitama, Japan
Institutions	Institute for Cosmic Ray Research, University of Tokyo
Education	Saitama Prefectural Kawagoe High School
Alma mater	Saitama University (B.S.) University of Tokyo (M.S., Ph.D.)
Doctoral advisor	Masatoshi Koshiba
Other academic advisors	Yoji Totsuka
Notable awards	Asahi Prize (1988) Bruno Rossi Prize (1989) Nishina Memorial Prize (1999) Panofsky Prize (2002) Japan Academy Prize (2012) Nobel Prize in Physics (2015) Fundamental Physics Prize (2016)
Spouse	Michiko

Takaaki Kajita (梶田 隆章, Kajita Takaaki^?, born 9 March 1959) is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. In 2015, he was awarded the Nobel Prize in Physics jointly with Canadian physicist Arthur B. McDonald.

Kajita was born in 1959 in Higashimatsuyama, Saitama, Japan. His wife, Michiko, lives in Toyama.

Kajita studied at the Saitama University and graduated in 1981. He received his doctorate in 1986 at the University of Tokyo. Since 1988 he has been at the Institute for Cosmic Radiation Research, University of Tokyo, where he became an assistant professor in 1992 and professor in 1999.

He became director of the Center for Cosmic Neutrinos at the Institute for Cosmic Ray Research (ICRR) in 1999. As of 2015^[update], he is at the Institute for the Physics and Mathematics of the Universe in Tokyo and Director of ICRR.

In 1998, Kajita's team at the Super-Kamiokande found that when cosmic rays hit the Earth's atmosphere, the resulting neutrinos switched between two flavours before they reached the detector under Mt. Kamioka. This discovery helped prove the existence of neutrino oscillation and that neutrinos have mass. In 2015, Kajita shared the Nobel Prize in Physics with Canadian physicist Arthur McDonald, whose Sudbury Neutrino Observatory discovered similar results. Kajita's and McDonald's work solved the longstanding Solar neutrino problem, which was a major discrepancy between the predicted and measured Solar neutrino fluxes, and indicated that the Standard Model, which required neutrinos to be massless, had weaknesses. In a news conference at the University of Tokyo, shortly after the Nobel announcement, Kajita said, "I want to thank the neutrinos, of course. And since neutrinos are created by cosmic rays, I want to thank them, too."