Related papers: Exclusive $J/\Psi$ and $\rho^0$ vector meson produ…
Vector meson photoproduction is an important probe of nuclear structure. Light vector mesons are most sensitive to low$-x$ structure, as long as they are not too light for perturbative QCD calculations. The $\rho'$ is of interest as an…
The exclusive $Z^0$ photoproduction at high energies in $\gamma p (A)$, $p p$ and $AA$ collisions is investigate within the color dipole formalism. We generalize the description of the deeply virtual compton scattering (DVCS) process, which…
Exclusive and semi-exclusive processes, the diffractive dissociation of hadrons into jets, and hard diffractive processes such as vector meson leptoproduction provide new testing grounds for QCD and essential information on the structure of…
We study exclusive diffractive production of vector mesons and photon using the color dipole model with leading Fock state light front wave functions derived from Dyson Schwinger and Bethe Salpeter equations. New results for the $\phi$…
The study of exclusive processes in ultraperipheral collisions at the Large Hadron Collider (LHC) has allowed us to test several aspects of the Standard Model and to search for New Physics. In this letter, we investigate the possibility of…
In this work we estimate the differential cross section for the high energy deeply virtual Compton scattering on a photon target within the QCD dipole-dipole scattering formalism. For the phenomenology, a saturation model for the…
We show that the lowest-order QCD calculation in a simple model of elastic vector-meson production does reproduce correctly the ratios of cross sections for rho, phi and J/psi, both in photoproduction and in high-Q2 quasi-elastic…
Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers…
We investigate the proposal that the rise with energy of the ratio of the exclusive photo-production cross-sections of vector mesons $\Psi(2s)$ and $J/\Psi$ can serve as an indicator for the presence of high gluon densities and associated…
A model for exclusive diffractive resonance production in proton-proton collisions at high energies is presented. This model is able to predict double differential distributions with respect to the mass and the transverse momentum of the…
Results on \jpsi production in $e p$ interactionsin the H1 experiment at HERA are presented. The \jpsi mesons are produced by almost real photons ($Q^2\approx 0$) and detected via their leptonic decays. The data have been taken in 1994 and…
The exclusive photoproduction of a pair of light mesons is studied within the framework of collinear factorisation. The amplitude factorises into a process-dependent perturbatively calculable hard part, a generalised parton distribution…
We report on an attempt to describe hard exclusive photoproduction of $J/\Psi$ mesons, i.e. the reaction $\gamma p \to J/\Psi p$, by means of a modified version of the hard-scattering approach, in which the proton is treated as a…
In the last years much work has been done to learn about the properties of the $\rho$-meson in nuclear matter. In a calculation of the in-medium spectralfunction of the $\rho$ we find that it is strongly modified by baryonic resonances,…
We explore QCD calculations for the process gamma p -> V X where V is a vector meson, in the region s >> -t and -t >> Lambda_QCD^2. We compare our calculations for the J/psi, phi and rho mesons with data from the ZEUS Collaboration at HERA…
In this letter we update our predictions for exclusive $J/\Psi$ and $\Upsilon$ photoproduction in proton-proton and nucleus - nucleus collisions at the Run 2 LHC energies obtained with the color dipole formalism and considering the impact…
We discuss exclusive vector meson electroproduction within the QCD collinear factorization framework. In Bjorken kinematics the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized…
The energy dependence of the cross section for exclusive electroproduction of vector mesons is discussed as a way to learn about the interplay of soft and hard interactions. The question of determining the scale of these processes is…
We present a nonperturbative QCD calculation of elastic $J/\psi$ meson production in photon-proton scattering at high energies. Using light cone wave functions of the photon and vector mesons, and the framework of the model of the…
We present predictions for the diffractive production of $\chi$ mesons in the central rapidity region usually covered by collider detectors. The predicted cross sections are based on the Bialas-Landshoff formalism for both exclusive and…