Prof. Yoishiro Nambu was born in 1921 in Tokyo. He received his Doctor of Science degree from the University of Tokyo in 1952. During the late 40's, when the subject of quantum electrodynamics was being formulated, he was associated with Prof. S. Tomonaga. In 1952, he was invited to the Institute for Advanced Study in Princeton. He became Professor of Physics at the University of Chicago in 1958, where, from 1974 to 1977, he was also Chairman of the Department of Physics. Nambu has made many important contributions to the development of elementary particle theory, including the introduction of the concept of spontaneous symmetry breaking for which he shared the 2008 Physics Nobel prize.


The spontaneous symmetry breaking model of hadron mass generation was developed by Nambu, together with Jona-Lasinio. This model is based on an analogy with the BCS theory of superconductivity. The modern version of the N(ambu)--J(ona)-L(asinio) Model is a low energy approximation to Quantum Chromodynamics. It also gives important insight into the nucleon-nucleon force, both in free space and in nuclei. Some features of nuclei, such as the approximate validity of the interacting boson model, appear to be due to a manifestation of spontaneous symmetry breaking due to the nuclear pairing interaction. The NJL model was originally proposed around 1960, before it was realized that nucleons are made up of three quarks. However, Nambu. with Han, did some pioneering work along these lines concerning gluons.


It is well known that photons are carriers of the force between electric charges. Nambu and Han generalized this idea to strong interactions, and proposed that the force between quarks is carried by gluons. In the original version of Nambu's work, the quarks were taken to have integral charges, but that was later corrected by Gell-Mann who introduced fractional charges.