Elastic Electroproduction of $\rh0$ and $J/\Psi$ Mesons at large $Q^2$   at HERA
  The total cross sections for the elastic electroproduction of $\rh0$ and $J/\Psi$ mesons for $Q^2$ $>$ 8 GeV$^2$ and $<W > \simeq 90$ GeV/c$^2$ are measured at HERA with the H1 detector. The measurements are for an integrated electron$-$proton luminosity of $\simeq$~3~pb$^{-1}$. The dependences of the total virtual photon$-$proton ($\gamma^* p$) cross sections on $Q^2$, $W$ and the momentum transfer squared to the proton ($t$), and, for the $\rho$, the dependence on the polar decay angle ($\cos \theta^*$), are presented. The $J/\Psi$ : $\rh0$ cross section ratio is determined. The results are discussed in the light of theoretical models and of the interplay of hard and soft physics processes. 
S. Aid, et al. (H1 Collaboration)