American physicist who was jointly awarded the 1976 Nobel Prize for Physics with Samuel C.C. Ting (Ting, Samuel C.C.) for the discovery of a new subatomic particle, the J/psi particle.

Richter studied at the Massachusetts Institute of Technology, Cambridge, where he received his doctorate in 1956. That same year he became a research associate at Stanford University, Stanford, Calif., becoming a full professor in 1967. He immediately undertook experiments that confirmed the validity of quantum electrodynamics at very short distances. In collaboration with David Ritson and with financial support from the Atomic Energy Commission, in 1973 he completed construction of the Stanford Positron-Electron Asymmetric Ring, a colliding-beam accelerator with which he discovered a new subatomic particle that he called the J-particle (now usually called the J/psi particle), the first of a new class of very massive, long-lived mesons. Ting, cowinner of the Nobel Prize, had made the same discovery independently.