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 research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of Roc ...

. Ōkubo worked primarily on

elementary particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and b ...

. 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( I ...

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 subparticles ...

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 classified ...

s in the

quark model In particle physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and antiquarks which give rise to the quantum numbers of the hadrons. The quark model underlies "flavor SU(3)", or the E ...

; this formula correctly predicts the relations of masses of the members of SU(3) multiplets in terms of

hypercharge In particle physics, the hypercharge (a portmanteau of hyperon, hyperonic and charge (physics), charge) ''Y'' of a subatomic particle, particle is a quantum number conserved under the strong interaction. The concept of hypercharge provides a sin ...

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 The University of Naples Federico II ( it, Università degli Studi di Napoli Federico II) is a public university in Naples, Italy. Founded in 1224, it is the oldest public non-sectarian university in the world, and is now organized into 26 depar ...

, in 1960/61 at

CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...

, 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 The J. J. Sakurai Prize for Theoretical Particle Physics, is presented by the American Physical Society at its annual April Meeting, and honors outstanding achievement in particle physics theory. The prize consists of a monetary award ($10,000 U ...

from the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ...

; ''"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 The is the oldest and most prestigious physics award in Japan. Information Since 1955, the Nishina Memorial Prize has been awarded annually by the Nishina Memorial Foundation. The Foundation was established to commemorate Yoshio Nishina, who w ...

in Japan and in 2006 the

Wigner Medal The International Colloquium on Group Theoretical Methods in Physics is an academic conference devoted to applications of group theory to physics. It was founded in 1972 by Henri Bacry and Aloysio Janner. It hosts a colloquium every two years. Th ...

. 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 INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1970 ...

{{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