was a Japanese theoretical physicist at the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private university, private research university in Rochester, New York. The university grants Undergraduate education, undergraduate and graduate degrees, including Doctorate, do ...

. Ōkubo worked primarily on elementary particle physics. He is famous for the

Gell-Mann–Okubo mass formula In physics, the Gell-Mann–Okubo mass formula provides a sum rule for the masses of hadrons within a specific multiplet, determined by their isospin (''I'') and strangeness (or alternatively, hypercharge) :M = a_0 + a_1 Y + a_2 \left I \left( ...

for

meson In particle physics, a meson ( or ) is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticle ...

s and

baryon In particle physics, a baryon is a type of composite subatomic particle which contains an odd number of valence quarks (at least 3). Baryons belong to the hadron family of particles; hadrons are composed of quarks. Baryons are also classi ...

s in the quark model; this formula correctly predicts the relations of masses of the members of SU(3) multiplets in terms of hypercharge and isotopic spin. Ōkubo began study at the

University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

in 1949 and received his bachelor's degree there in 1952. He became a graduate student at the

in 1954, where he earned his PhD in 1958 with David Feldman as thesis advisor. Afterwards, he was a postdoc in 1959/60 at the University of Naples, in 1960/61 at CERN, and then in 1962 began researching again at the University of Rochester, where he became a professor in 1964 and retired in 1996 as an emeritus professor. In 2005 he received the Sakurai Prize from the American Physical Society; ''"For groundbreaking investigations into the pattern of hadronic masses and decay rates, which provided essential clues into the development of the quark model, and for demonstrating that CP violation permits partial decay rate asymmetries"''.Susumu Okubo - 2005 J. J. Sakurai Prize Winner
/ref> In 1976 Ōkubo received the Nishina Memorial Prize in Japan and in 2006 the Wigner Medal. In 1966 he was a

Guggenheim Fellow Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the ar ...

and in 1969 a Ford Fellow. He was a member of the American Physical Society and the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings ...

. Ōkubo died in July 2015.

Works

* ''Introduction to Octonion and Other Non-Associative Algebras in Physics''. Cambridge University Press, 1995

References

External links

Biography from the University of Rochester

Okubo on the discovery of the mass formula
(pdf file, 92 kB)
Scientific publications of Susumu Okubo
on INSPIRE-HEP {{DEFAULTSORT:Okubo, Susumu Japanese physicists 1930 births 2015 deaths J. J. Sakurai Prize for Theoretical Particle Physics recipients Mathematical physicists People associated with CERN Theoretical physicists Fellows of the American Physical Society