Friedman, Jerome Isaac

(1930– ) US physicist: confirmed experimentally the concept of quarks.

Friedman studied in his native Chicago and at Stanford before working at MIT, where he became professor of physics in 1967. With Henry Kendall (1926–99) and Richard Taylor (1929– ) he shared the 1990 Nobel Prize for physics. All three had used highly accelerated electrons scattered by protons and neutrons to successfully test the quark model in particle physics, working together on the ‘SLAC-MIT’ experiment. This used inelastic collisions involving electrons to observe inner structure within the protons and neutrons in the nucleus. This confirmed experimentally the theoretical postulate of these being made up of quarks, put forward in 1964 by and G Zweig (1937– ) The three carried out the experiments at the Stanford Linear Accelerator Center (SCLAC) between 1967 and 1973, using a high-energy electron beam striking a hydrogen or deuterium target. This work also confirmed that quarks have spin ½, and fractional charge of either +? or –? e .