Related papers: J/\psi production through resolved photon processe…
We compute cross sections for incoherent and coherent diffractive J/Psi production in ultraperipheral nucleus-nucleus and proton-nucleus collisions using two different dipole models fitted to HERA data. We obtain a reasonably good…
The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of $J/\psi$ vector mesons off proton targets in ultra-peripheral p-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}} = 5.02$…
We study the photoproduction of the vector mesons $\Phi$ and $J/\Psi$ off a proton in the kinematical regime of large energies and scattering angles within the framework of perturbative QCD. Our investigations are based on the hard…
In these proceedings we present our results on the exclusive photoproduction of $J/\psi\,\eta_{c}$ pairs in the collinear factorization framework. We argue that the process might be used as a complementary channel for studying the…
Charmonium production and absorption in heavy ion collisions is studied with the Ultrarelativisitic Quantum Molecular Dynamics model. We compare the scenario of universal and time independent color-octet dissociation cross sections with one…
Recently, significant enhancements of J/$\psi$ production at very low transverse momenta were observed by the ALICE and STAR collaboration in peripheral hadronic A+A collisions. The anomaly excesses point to evidence of coherent…
We proceed for the first time to the evaluation of the Born cross section for J/psi+eta(c) production, namely via g+g -> J/psi+eta(c)+g, and show that it has a harder P_T spectrum than the J/psi-pair yield at Born level. If one stuck to a…
We studied the photoproduction of $\psi^{\prime}$ in the forward regions in polarized $\gamma p$ collisions at relevant HERA energies. We found that this reaction is very effective to test the color-octet mechanism which is based on the…
The comparison of $J/\psi$ photoproduction data in the inelastic region with theoretical predictions based on the NRQCD approach has remained somewhat ambiguous and controversial, in particular at large values of the inelasticity variable…
We firstly examine hadroproduction of prompt J/psi's at the Fermilab Tevatron in a Monte Carlo Framework by means of the event generator PYTHIA 5.7 in which those colour-octet matrix elements processes relevant for charmonium production…
We make predictions for the cross section of coherent $J/\psi$ photoproduction in Pb-Pb and O-O ultraperipheral collisions (UPCs) at the LHC as a function of the $J/\psi$ rapidity $y$ in the framework of collinear factorization and…
The double J/psi production in p\bar{p} collision is revisited. It is found that the J/\psi pair production rate at leading order with p_T > 4 GeV in conventional scheme is larger than the rate derived from color-octet mechanism by a factor…
Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultra-peripheral collisions (UPCs) at…
A detailed theoretical derivation of the cross sections of $e^+e^- \to e^+e^-$ and $e^+e^- \to \mu^+\mu^-$ around the $J/\psi$ resonance is reported. The resonance and interference parts of the cross sections, related to $J/\psi$ resonance…
The exclusive electroproduction of J/psi mesons, ep->epJ/psi, has been studied with the ZEUS detector at HERA for virtualities of the exchanged photon in the ranges 0.15<Q^2<0.8 GeV^2 and 2<Q^2<100 GeV^2 using integrated luminosities of 69…
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…
In this work we investigate the $J/\psi$ production in proton-proton collisions at the center-of-mass energy ($\sqrt{s}$) equal to 2.76, 5.02, 7, 8 and 13 TeV with a parton and hadron cascade model PACIAE 2.2a. It is based on PYTHIA but…
We calculate the cross sections of inclusive J/psi production in photoproduction and two-photon scattering, involving both direct and resolved photons, and in e^+e^- annihilation at next-to-leading order (NLO) within the factorization…
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 coherent J/$\psi$ photoproduction cross section is measured for the first time at midrapidity in peripheral to semicentral Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. The centrality differential cross section ${\rm d} \sigma/…