Meson dominance of hadron form factors and large-Nc phenomenology
  We discuss the pion and nucleon form factors and generalized form factors within the large-Nc approach in the space-like region. We estimate their theoretical uncertainties through the use of the half-width rule, amounting to taking the half-width of the resonances as the deviation of their mass parameters. The approach embodies the meson dominance of form factors and the high-energy constraints from perturbative QCD. We compare the results with the available experimental data and lattice simulations. The meson-dominance form factors are generally comparable to the available experimental data within the half-width-rule uncertainties. Our errors are comparable to the experimental uncertainties, but are smaller than lattice errors. 
Pere Masjuan, Enrique Ruiz Arriola, and Wojciech Broniowski
hep-ph hep-lat nucl-th