Makoto Kobayashi
In 1973, Makoto Kobayashi and Toshihide Maskawa predicted the existence of a third generation of quarks to explain observed CP violations in kaon decay. The names top and bottom were introduced by Haim Harari in 1975, to match the names of the first generation of quarks (up and down) reflecting the fact that the two were the "up" and "down" component of a weak isospin doublet.