Maskawa, Toshihide (1940-2021), a Japanese physicist, won a share of the 2008 Nobel Prize in physics. He shared the prize with fellow Japanese physicist Makoto Kobayashi . Together, they identified the origin of a particular broken symmetry, an important kind of relationship among subatomic particles. Subatomic particles are pieces of matter smaller than atoms. Kobayashi and Maskawa’s work predicted the existence of a new family of particles, which were later discovered. Their work built on a theory of broken symmetry proposed by the Japanese-born American physicist Yoichiro Nambu , who also won a share of the prize.
In particle physics, scientists use the term symmetry to describe the idea that for every subatomic particle , there exists an opposite particle with similar properties. For example, the electron has the positron, a similar particle with an opposite electrical charge. However, scientists think that if such particle pairs shared a perfect symmetry, the universe could not exist as we know it. Thus, they thought that the particles must share a symmetry that is somehow incomplete or “broken.” In 1960, Nambu proposed a mathematical description of broken symmetry that could be applied to subatomic particles. But scientists did not have a model of subatomic physics with the right particles to fit this theory.
In 1972, Kobayashi and Maskawa proposed a model of the subatomic physics that included a new family of quarks, a type of subatomic particle. These two new quarks helped explain the theory of how broken symmetry occurs. Scientists announced the discovery of the last of the proposed quarks in 1995. Kobayashi and Maskawa’s work helped in the development of the Standard Model , a fundamental theory of physics that describes all the basic subatomic particles and their interactions.
Maskawa was born on Feb. 7, 1940, in Nagoya, Japan. He received his doctorate degree from the University of Nagoya in 1967. He remained at the university as a research assistant until 1970. He then worked as a research assistant at Kyoto University until 1976. From 1976 to 1980, Maskawa was a professor at the University of Tokyo. He then became a professor at Kyoto University’s Yukawa Institute for Theoretical Physics, and served as the director of the institute from 1997 to 2003. From 2009 to 2018, he was a professor at Nagoya University, and the director of its Kobayashi-Maskawa Institute for the Origin of Particles and the Universe. Maskawa died on July 23, 2021.
See also Kobayashi, Makoto ; Nambu, Yoichiro ; Standard Model .
