Related papers: Diffractive Vector Meson Production with a Large M…
By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the…
The elastic production of vector mesons at HERA is discussed from the theoretical point of view. We briefly review different models, their successes and shortcomings. Main emphasis is put on recent issues in perturbative QCD calculations.…
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…
In this talk, the recent data on diffractive electron-proton interactions at HERA are reviewed. The question of diffraction as a soft or hard process is addressed and discussed in the context of inclusive diffraction, vector meson…
The HERA collider experiments H1 and ZEUS have established extensive measurement programs for diffractive vector-meson production processes during the first six years of their operation. The results provide stringent phenomenological tests…
The diffractive process $\gamma^*(Q^2) p\to V+X$ (where $V= \rho^0, \omega , \phi$ are the vector mesons, consisted of light quarks, $X$ represents the hadrons to that a proton dissociates) is studied. We consider the region of large…
An extended study of exclusive vector meson production in e,p interactions has been performed by the H1 and the ZEUS collaborations at the HERA collider. Recent measurements are reported and discussed within the framework of the dipole…
The latest results on exclusive vector meson electroproduction from HERA are reviewed. In particular, the new high-statistics measurements of the rho^0 electroproduction are presented and compared to several models.
In this work the production of vector mesons in diffractive DIS is analyzed, with an emphasis on the impact of the internal spin structure of a vector meson upon its virtual photoproduction rate. We derived the full sets of s-channel…
A compilation of H1 and ZEUS cross section measurements for elastic vector meson production is presented as a function of the scale $K^2 = (Q^2+M_V^2)/4$, where Q^2 is the exchanged photon virtuality and M_V is the mass of the vector meson.…
We discuss recent preliminary results on the diffractive photoproduction of {\rhoz}, $\phi$, and {\jpsi} mesons at high momentum transfer reported by the ZEUS collaboration at HERA. A special-purpose calorimeter served to tag the quasi-real…
The diffractive process $\gamma p\to V + X$ (where $V$ is a vector meson and $X$ results from the dissociation of the proton) is studied. In particular, we consider the region of large momentum transfer (i.e. $|t|\gg\Lambda_{QCD}^2$) and…
New results on elastic electroproduction and proton-dissociative photoproduction at large t of rho, phi and J/psi mesons are presented. They are interpreted within perturbative QCD.
Diffractive meson production at HERA offers interesting possibilities to investigate diffractive processes and thus to learn something about the properties of the pomeron. The most succesful phenomenological description of the pomeron so…
At the HERA collider the experiments H1 and ZEUS have studied the exclusive production of vector mesons over a wide kinematical range. A selection of recent measurements of the cross sections has been presented at Moriond QCD 2003.
Elastic and proton-dissociative photoproduction of $\rho^0$, $\phi$ and $J/\psi$ vector mesons ($\gamma p\to Vp$, $\gamma p\to VN$, respectively) have been measured in e^+p interactions at HERA up to -t=3 GeV$^2$, where t is the…
A successful interpretation of the cross sections for elastic and inelastic vector meson production can be made if one assumes the underlying dynamics to be governed by hard partonic subprocesses. Extending these partonic approaches to…
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…
Results on elastic vector meson production at HERA are presented in the framework of perturbative QCD. The energy dependence of the cross section for J/Psi photoproduction and for rho electroproduction is studied. A full polarisation…
Through an analysis of diffractive vector meson production, we show that the proton appears quite dense to a small size probe at present HERA energies. This means that saturation effects are already important.