Related papers: The Wave Function of 2S Radially Excited Vector Me…
In this work the double vector meson production in two-photon interactions at high energies is investigated considering saturation physics. We extend the color dipole picture for this process and study the energy and virtuality dependence…
We employ a parameterisation of the proton dipole cross section previously extracted from electroproduction and photoproduction data to predict the diffractive structure function F2D(3)(Q^2, beta, xpom). Comparison with HERA H1 data yields…
We confront a very wide body of HERA diffractive electroproduction data with the predictions of the colour dipole model. We focus upon three different parameterisations of the dipole scattering cross-section and find good agreement for all…
Inelastic and diffractive production of J/psi mesons at HERA is reviewed. The data on inelastic photoproduction are described well within errors by the Colour Singlet Model in next-to-leading order. A search for colour octet processes…
The QCD dipole picture allows to build an unified theoretical description -based on BFKL dynamics- of the total and diffractive nucleon structure functions measured at HERA. We use a four parameter fit to describe the 1994 H1 proton…
Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by…
Including destructively interfering off-diagonal transitions of diffraction-dissociation type, we arrive at a formulation of GVD for exclusive vector-meson production in terms of a continuous spectral representation of dipole form. The…
We use data on the deep inelastic structure function F_2 in order to constrain the cross-section for scattering a colour dipole off a proton. The data seem to prefer parameterisations which include saturation effects. That is they indicate…
We observe that the DGLAP evolution equations at NNLO analysis predicts a ratio of the structure functions in region of small Bjorken variable $x$. The ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ is obtained and compared with the prediction of…
The diffractive t-slope, B_V, of elastic charmonia (V=J/psi, psi') photo- and leptoproductions off a nucleon is studied at low |t| (< 1 GeV^2) in the leading logarithmic approximation of perturbative QCD, with a special emphasis on the…
Consistency of the previously suggested color-dipole representation of deep-inelastic scattering (DIS_) and vector-meson production at low x with DGLAP evolution allows one to predict the exponent of the W^2 dependence of the saturation…
QED radiative corrections to the cross section of diffractive electro- and photoproduction of vector mesons is calculated at HERA energies. Both semi-analytical and Monte Carlo approaches are discussed and compared.
We study the photoproduction of vector mesons off proton and off nuclear targets. We work within the colour dipole model in an approach that includes subnucleon degrees of freedom, so-called hot spots, whose positions in the…
Predictions for the diffractive photoproduction of the $\Upsilon$-family at HERA energies, within the framework of the analysis by Frankfurt, Koepf and Strikman, are presented. Two novel effects lead to a significant enhancement of the…
We present a review of the latest exclusive diffraction results achieved at HERA, discussing in particular the $W$ and $t$ dependence of the measured cross-sections in both DIS and photo-production regimes.
The exclusive production of vector mesons in deep inelastic scattering is a hard scattering process with the well controlled size of quark configurations which dominate the production amplitude. This allows an unambiguous prediction of…
The energy dependence of the cross sections for electromagnetic diffractive processes can be well described by a single power, $W^\delta$. For $J/\psi$ photoproduction this holds in the range from 20 GeV to 2 TeV. This feature is most…
Using the QCD dipole picture of BFKL dynamics, the quasi elastic component of the diffractive gamma*-dipole cross-section, dominating at small M^2/Q^2, is calculated.
We discuss two different models for the impact parameter dependent dipole cross section: one based on DGLAP evolution and the other inspired by the Balitsky-Kovchegov equation. The parameters are determined from fits to data on the total…
We predict the dependence on energy of photo(electro) production processes: $\gamma(\gamma^*)+p\to V+ X$ with large rapidity gap at small x and large momentum $-t$ transferred to $V$ in pQCD. Here V is a heavy quarkonium ($J/\psi,…