Implications of new nucleon form factor data for thepredictions of the extended Gari-Kruempelmann model
In 2002 I published an extended Gari-Krumpelmann model of the nucleon form factors that incorporated vector dominance and evolved to pQCD behavior at high momentum transfer. Polarization data for R_n and R_p, some preliminary, was included. A good fit was obtained to all the form factors, except for the G_En and G_Ep differential cross section data that was inconsistent with the polarization data. Since then, final versions of the polarization data have been published and have been used to refit the model parameters. Only R_n and G_En predictions change significantly. They still differ importantly from the differential cross section results, but now are much larger than the Galster curve. Also since 2002 attention has been given to apparent structure in the data at low momentum transfer, ~ 0.2 (GeV/ C)^2. The model shows similar structure in several of the form factors.