Quark
The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968. Accelerator experiments have provided evidence for all six flavors. The top quark, first observed at Fermilab in 1995, was the last to be discovered.
Jerome Isaac Friedman
In 1968-69, commuting between MIT and California, he conducted experiments with Henry W. Kendall and Richard E. Taylor at the Stanford Linear Accelerator Center which gave the first experimental evidence that protons had an internal structure, later known to be quarks. For this, Friedman, Kendall and Taylor shared the 1990 Nobel Prize in Physics. He is an Institute Professor at the Massachusetts Institute of Technology. Friedman is also a member of the Board of Sponsors of the Bulletin of the Atomic Scientists.