Diffractive Rho Meson Electroproduction at High Q^2 and High |t|
  The electroproduction of rho mesons is studied at HERA with the H1 detector at high Q^2 and high |t|. Cross sections are measured as a function of Q^2, W and t. The W dependence of the gamma*-p cross section is observed to increase with Q^2 from values compatible with soft Pomeron exchange at low Q^2 to a hard dependence at large Q^2. Spin density matrix elements are measured and their dependence is compared with a two gluon exchange model. 
Xavier Janssen