Large t diffractive J / ψ photoproduction with proton dissociation in ultraperipheral pA collisions at LHC

We evaluate the large momentum transfer J / ψ photoproduction with rapidity gaps in ultraperipheral proton-ion collisions at the LHC which provides an effective method of probing dynamics of large t elastic hard QCD Pomeron interactions. It is shown that the experimental studies of this process would allow to investigate the energy dependence of cross section of elastic scattering of a small c over(c, ̄) dipole off the gluon over a wide range of invariant energies 10³ < s_{c over(c, ̄) - gluon} < 10⁶ GeV². The accessible energy range exceeds the one reached in γp at HERA by a factor of 10 and allows the kinematic cuts which improve greatly sensitivity to the Pomeron dynamics as compared to the HERA measurements. The cross section is expected to change by a factor ≥20 throughout this interval and our estimates predict quite reasonable counting rates for this process with the several of the LHC detectors.