The interaction between constituent quarks

The symmetry structure and the dynamical mechanisms that underlie the effective interaction between constituent quarks are discussed. The need for a flavor dependent hyperfine interaction is emphasized. Such a hyperfine interaction arises from exchange of the octet of light pseudoscalar mesons, which are the Goldstone bosons of the approximate chiral symmetry of QCD, between the quarks. The role of gluon exchange between quarks is small, but gluonic ''dressing'' of the meson exchange interaction is important for eliminating the tensor component of the meson exchange interaction. (author)