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.
Luciano Maiani
Luciano Maiani has authored over 100 scientific publications on the theory of elementary particles often with several co-authors. In 1970 he predicted the charmed quark in a paper with Glashow and Iliopoulos which was later discovered at SLAC and Brookhaven in 1974 and led to a Nobel Prize in Physics for the discoverers. Working with Guido Altarelli in 1974 they explained that the observed octet enhancement in weak non-leptonic decays was due to a leading gluon exchange effect in quantum chromodynamics. They later extended this effect to describe the weak non-leptonic decays of charm and bottom quarks as well and also produced a parton model description of heavy flavor weak decays. In 1976 Maiani analyzed the CP violation in the six-quark theory and predicted the very small electric dipole moment of the neutron. In the 1980s he started using the numerical simulation of lattice QCD and this led to the first prediction of the decay constant of pseudoscalar charmed mesons and of B mesons. A proponent of supersymmetry, Maiani once said that the search for it was "primary goal of modern particle physics".
He has not confined his interest to the theoretical side of physics either, with involvement in ALPI, EUROBALL, DAFNE, VIRGO and the LHC.