Japanese scientist who was a corecipient, with Yoichiro Nambu (Nambu, Yoichiro) and Maskawa Toshihide, of the 2008 Nobel Prize for Physics. Kobayashi and Maskawa shared half the prize for their discovery of the origin of broken symmetry, which created at least six quarks (quark) moments after the big bang (big-bang model).

In 1972 Kobayashi and Maskawa proposed that CP violation (the violation of the combined conservation laws (conservation law) associated with charge conjugation 【C】 and parity 【P】 by the weak force) is an inherent property of the standard model of subatomic particles (subatomic particle) if there exist at least two additional quarks beyond the four “flavours” (up, down, charm, and strange) known at that time. These two new quark flavours were experimentally confirmed in 1977 (bottom quark) and 1995 (top quark).

Kobayashi received a Ph.D. from Nagoya University in 1972. He later taught at the High Energy Accelerator Research Organization (KEK) in Japan, becoming professor emeritus in 2006.