Large t diffractive rho-meson photoproduction with target dissociation   in ultraperipheral pA and AA collisions at LHC
  We demonstrate that study of large t vector meson photoproduction with rapidity gaps in ultraperipheral proton-ion and ion-ion collisions at LHC would allow to investigate the energy dependence of cross section of elastic scattering of a small dipole off the parton over a wide range of energies $10^3 < s_{dipole - parton} < 10^6 GeV^2$ where this cross section is expected to change by a factor $\ge 20$. The accessible energy range exceeds the one reached at HERA by a factor of 10 both in $\gamma p$ and in $\gamma A$ scattering. In addition, study of A-dependence of this process will allow to determine the t range where interaction of small dipoles gives the dominant contribution and to investigate effects of absorption for the propagation of ultrarelativistic small $q\bar q$ dipoles through the nuclear media and probe in a novel way onset of the black disk regime. 
L.Frankfurt (TAU), M.Strikman (PSU) and M.Zhalov (PNPI)