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Diffractive photoproduction of rho, phi and J/psi was studied in the BFKL approach to hard colour singlet exchange. Differential cross sections, the energy dependence and spin density matrix elements were calculated and compared to data from HERA. The overall description of data is reasonably good, except of the single flip amplitude which has the wrong sign. Importance of chiral odd components of the photon is stressed.
We consider the contribution to our understanding of vacuum-exchange processes to be made by investigations at the proposed electron-proton collider THERA. Recent results have highlighted the value of such studies for testing quantum chromodynamical
We discuss diffractive photon-production of vector mesons in holographic QCD. At large $sqrt{s}$, the QCD scattering amplitudes are reduced to the scattering of pair of dipoles exchanging a closed string or a pomeron. We use the holographic construct
The collinear factorization framework allows to describe the exclusive photoproduction of a $gamma,rho$ pair in the generalized Bjorken regime in terms of a perturbatively calculable coefficient function and universal generalized parton distributions
We apply perturbative QCD to investigate the near threshold heavy quarkonium photoproduction at large momentum transfer. From an explicit calculation, we show that the conventional power counting method will be modified and the three quark Fock state
The differential cross section, $dsigma/dt$ for $omega$ meson exclusive photoproduction on the proton above the resonance region ($2.6<W<2.9$ GeV) was measured up to a momentum transfer $-t = 5$ GeV$^2$ using the CLAS detector at Jefferson Laboratory