(1931––) American physicist
Richter was joint winner of the 1976 Nobel Prize for physics. A New Yorker by birth, he studied first at the Massachusetts Institute of Technology, gaining his BS in 1952 and his PhD in physics in 1956. His interest in the physics of elementary particles took him subsequently to Stanford University's high-energy physics laboratory where he became a member of the group building the first pair of electron- storage rings. In this machine, intense beams of particles were made to collide with each other in order to study the validity of quantum electrodynamic theory.
In the 1960s, Richter designed the Stanford Positron Electron Accelerating Ring (SPEAR), which was capable of engineering collisions of much more energetic particles. It was on this machine that, in November 1974, Richter and his collaborators created and detected a new kind of heavy elementary particle, which they labeled psi (ψ). The discovery was announced in a 35-author paper (typical of today's high-energy-research teams) in the journal Physical Review Letters. The particle is a hadron with a lifetime about one thousand times greater than could be expected from its observed mass. Its discovery was important as its properties are consistent with the idea that it is formed from a fourth type of quark, thus supporting Sheldon Glashow's concept of ‘charm’.
Almost simultaneously, another group led by Samuel Ting 2000 miles away at the Brookhaven Laboratory, Long Island, made the same discovery independently in a very diffferent experiment. Richter and Ting met to discuss their findings, and confirmation came quickly from other laboratories when they knew the energy of the new particle and were able to tune their own machines accordingly. Ting called the new particle J; it is now usually referred to as the J/psi in recognition of the simultaneity of its discovery. The discovery led to the finding of many other similar particles as a ‘family’ and has stimulated new attempts to rationalize the underlying structure of matter. Within only two years, Richter and Ting were to be the recipients of the Nobel Prize for physics.
Richter has been a full professor at Stanford University since 1967, taking a sabbatical year at the European Organization for Nuclear Research (CERN) in Geneva (1975–76). He became director of the Linear Accelerator Center in 1984.
Subjects: Science and Mathematics.