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.
Franz N. D. Kurie
Franz Newell Devereux Kurie (February 6, 1907 in Victor, Colorado – June 12, 1972) was an American physicist who, while working at Yale in 1933, showed that the neutron was neither a dumbbell-shaped combination of proton and electron, nor an onion-shaped combination of an electron embracing the proton. Consequently, and until the discovery of the quark structure of hadrons, the neutron was assumed to be an elementary particle.