A Unified Vector-Meson Dominant Model of Pion Electromagnetic Form Factor and Production

The vector-meson dominance model, extended to evolve to asymptotic QCD, successfully models in one formula both the space-like nucleon electromagnetic form-factor and time-like electromagnetic production of nucleons. The necessary analyticity to connect the two regions is obtained by finding and subtracting the real poles. We show that this same approach is successful in fitting the pion electromagnetic form factor simultaneously with the electromagnetic production of pions. A key component is the rho-omega interference.