Pion electromagnetic form factor, perturbative QCD, and large-Nc Regge   models
  We present a construction of the pion electromagnetic form factor where the transition from large-Nc Regge vector meson dominance models with infinitely many resonances to perturbative QCD is built in explicitly. The construction is based on an appropriate assignment of residues to the Regge poles, which fulfills the constraints of the parton-hadron duality and perturbative QCD. The model contains a slowly falling off non-perturbative contribution which dominates over the perturbative QCD radiative corrections for the experimentally accessible momenta. The leading order and next-to-leading order calculations show a converging pattern which describes the available data within uncertainties, while the onset of asymptotic QCD takes place at extremely high momenta, Q ~ 10^3-10^4 GeV. The method can be straightforwardly extended to study other form factors where the perturbative QCD result is available. 
Enrique Ruiz Arriola, Wojciech Broniowski