A Variational Study of the Nucleon Wavefunction
  The structure of the nucleon is studied variationally on the lattice by maximizing the overlap between the nucleon and a trial function generated by an interpolating field containing variational parameters. We examine the effect of the spatial extent of smeared quark sources, the degree of gauge field smearing, the positions of smeared quark sources, inclusion of lower Dirac components and of diquark substructure. Exploratory calculations with quenched Wilson fermions at a pion mass of 900 MeV achieved overlaps as high as 80%, and there was no evidence of diquark substructure. 
Jonathan Bratt and J. W. Negele