Toshihide Maskawa (or Masukawa) (益川 敏英 Masukawa Toshihide?, born February 7, 1940 in Nagoya, Japan) is a Japanese theoretical physicist known for his work on CP-violation who was awarded one quarter of the 2008 Nobel Prize in Physics "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."
A native of Aichi Prefecture, Maskawa graduated from Nagoya University in 1962 and received a Ph.D in particle physics from the same university in 1967. At Kyoto University in the early 1970s, he collaborated with Makoto Kobayashi on explaining broken symmetry (the CP violation) within the Standard Model of particle physics. Maskawa and Kobayashi's theory required that there be at least three generations of quarks, a prediction that was confirmed experimentally four years later by the discovery of the bottom quark.
Maskawa and Kobayashi's 1973 article, "CP Violation in the Renormalizable Theory of Weak Interaction", is the fourth most cited high energy physics paper of all time as of 2009. The Cabibbo–Kobayashi–Maskawa matrix, which defines the mixing parameters between quarks was the result of this work. Kobayashi and Maskawa were jointly awarded half of the 2008 Nobel Prize in Physics for this work, with the other half going to Yoichiro Nambu.
Maskawa was Director of the Yukawa Institute for Theoretical Physics from 1997 to 2003. He is now special professor and director general of Kobayashi-Maskawa Institute for the Origin of Particles and the Universe at Nagoya University, director of Maskawa Institute for Science and Culture at Kyoto Sangyo University and professor emeritus of Kyoto University .
- "The Nobel Prize in Physics 2008".The Nobel Foundation. Retrieved 2009-10-17.
- M. Kobayashi, T. Maskawa (1973). "CP-Violation in the Renormalizable Theory of Weak Interaction". Progress of Theoretical Physics 49 (2): 652–657. Bibcode:1973PThPh..49..652K.doi:10.1143/PTP.49.652.
- "Top Cited Articles of All Time (2009 edition)". SLAC. 2009. Retrieved 2010-02-28.
- "History of YITP". Yukawa Institute for Theoretical Physics.