Susumu Okubo (born 22.02.1930) is a Japanese theoretical physicist. He was born in Tokyo. He graduated from the University of Tokyo (1952). Since 1957 he has worked at the University of Rochester in the USA (professor from 1964).
His research was in the theory of elementary particles. In 1958 he pointed out that the violation of CP invariance should entail a difference in the partial probabilities of charge-conjugate reactions, and that CPT invariance entails exact charge symmetry of the masses and total decay probabilities (the Okubo effect). In 1959, together with R. Marshak, he postulated the lepton-hadron analogy, and in 1960—61 he proposed a nonlinear theory of elementary particles. In 1962 he gave a general mass formula for any unitary multiplet (the Gell-Mann — Okubo equation).
Y. Nishina Prize.