Understanding Hadron Structure Using Lattice QCD
  An elementary introduction is presented to the study of hadron structure using lattice QCD. Following a brief review of relevant aspects of path integrals, the discrete lattice path integral is presented for gluon and quark fields and used to calculate physical observables. Essential aspects of instanton physics are reviewed, and it is shown how the instanton content is extracted from lattice gluon configurations. Finally, both comparison of results including all gluons with those including only instantons and the study of quark zero modes associated with instantons and their contributions to hadronic observables are used to show the dominant role of gluons in hadron structure. 
J.W. Negele