Strange quark
The first strange particle (a particle containing a strange quark) was discovered in 1947 (kaons), but the existence of the strange quark itself (and that of the up and down quarks) was only postulated in 1964 by Murray Gell-Mann and George Zweig to explain the Eightfold Way classification scheme of hadrons. The first evidence for the existence of quarks came in 1968, in deep inelastic scattering experiments at the Stanford Linear Accelerator Center. These experiments confirmed the existence of up and down quarks, and by extension, strange quarks, as they were required to explain the Eightfold Way.
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.