t-dependences of vector meson diffractive production in ep collisions
  We calculate $p_T$-dependences of diffractive vector meson photo- and electroproduction in electron-proton collisions with and without proton dissociation at small momenta transfers. The calculated slopes are in good agreement with the data. 
M.G.Ryskin, Yu.M.Shabelski, A.G.Shuvaev (Petersburg Nuclear Physics   Institute)