Successful description of exclusive vector meson electroproduction
  Data for the differential cross sections for $\gamma^* p\to\rho^0 p$, $\gamma^* p \to \phi p$ and $\gamma^* p\to J/\psi p$, at all available values of $Q^2$, fit very well to a combination of soft pomeron, hard pomeron and $f_2$ exchange. 
A. Donnachie and P. V. Landshoff