Related papers: Inelastic $J/\psi$ photoproduction
We investigate the J/psi polarization in photoproduction at the Hadron Electron Ring Accelerator(HERA) up to the next-to-leading order of QCD. The results show that the transverse momentum p_t and energy fraction z distributions of J/psi…
We evaluate the large momentum transfer $J/\psi$ 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.…
According to quantum chromodynamics, at sufficiently high energy, the structure of hadrons reveals a dynamic equilibrium between gluon splitting and gluon recombination -- a phenomenon known as saturation. The process of diffractive…
The electroproduction of J/psi and psi(2S) mesons is studied in elastic, quasi-elastic and inclusive reactions for four momentum transfers 2 < Q^2 < 80 GeV^2 and photon-proton centre of mass energies 25 < W < 180 GeV. The data were taken…
The nuclear enhancement observed in inelastic photoproduction of $J/\Psi$ should not be interpreted as evidence for an increased gluon density in nuclei. The nuclear suppression of the production rate due to initial and final state…
In the framework of the $k_T$-factorization approach, we analyse the inclusive and inelastic production of $J/\psi$ particles in deep inelastic $ep$ scattering. We take into account both colour-singlet and colour-octet production channels.…
The coherent and incoherent $J/\Psi$ photoproduction in $PbPb$ collisions are investigated considering the possible states of nucleon configurations in the nuclear wave function and taking into account of the non - linear corrections to the…
The inelastic production of J/psi mesons in e p collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of 109 pb-1. The J/psi mesons were identified using the decay channel J/psi -> mu+ mu-. The…
Based on a perturbative theory of quantum chromodynamics and non-relativistic quark model, associated $J/\psi$ plus open charm photoproduction on charm quarks in a proton via partonic subprocess $\gamma c\to J/\psi c$ is discussed. It is…
The H1 Collaboration recently reported a new analysis on the inelastic photo- production of J/\psi mesons at DESY HERA ep collider. We show that these new experimental results are well described by the Color Evaporation Model for quarkonium…
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…
Approximately taking into account the higher-order effects due to multiple-gluon initial-state radiation, we extract from the latest Tevatron data of prompt J/psi hadroproduction the leading colour-octet matrix elements within the…
Using the general notion of cross section fluctuations in hadron--nucleus scattering at high energies, we derive an expression for the cross section of incoherent $J/\psi$ photoproduction on heavy nuclei $d\sigma_{\gamma A \to J/\psi…
We consider J/psi meson photoproduction on protons at high energies at the leading order in alpha_s using conventional parton model and k_t-factorization approach of QCD. It is shown that in the both cases the colour singlet mechanism gives…
The production of $J/\psi$-pairs as a possible measure of the polarized gluon distribution $\Delta G(x)$ is studied for proton--nucleon collisions at $\sqrt{s} =40\;\mbox{GeV}^2$ (HERA-$\vec{{\rm N}}$). Possibilities of reconstructing the…
This report is a short overview of experimental and theoretical results in J/psi production in electron-proton collisions at DESY HERA with special focus lying on recent developments in inelastic photoproduction.
The prediction of single-spin asymmetry in inelastic photoproduction of $J/\psi$ in $ep^\uparrow$ collision is presented. At next-to-leading order, the dominating process is photon-gluon fusion, $\gamma+g\rightarrow J/\psi+g$ for the…
We quantify perturbative and non-perturbative QCD effects in the exclusive $J/\psi$-photoproduction cross section, and in the shrinkage of the differential cross section with respect to momentum transfer, $t$. We predict that in the high…
I discuss the impact of color-octet contributions and higher-order QCD corrections on the cross section for inelastic $J/\psi$ photoproduction. The theoretical predictions are compared with recent experimental data obtained at HERA.
We study the diffractive electroproduction of quarkonia from quark-antiquark-gluon states in the photon wave function. We show that these states contribute to the leading-power and leading-logarithm level. We suggest the measurement of…