Quarks, Gluons, and Jets
The quanta of quantum chromodynamics, 1974–1982.
The striking success of the parton model in describing deep inelastic’nucleon and neutrino’nucleon scattering provided strong circumstantial evidence for the Feynman’Bjorken picture and for its complete elaboration as quantum chromodynamics (QCD). QCD describes all strong interactions as resulting from the interactions of spin-1/2 quarks and spin-1 gluons. The fundamental coupling is of the gluon to the quarks, in a fashion analogous to the coupling of a photon to electrons. In addition, the gluons couple directly to each other. SU(3) plays a central role. Just as in the Gell-Mann–Zweig model of hadrons, there are three basic constituents. The u quark, for example, ...