Related papers: $J/\psi$ at small-$x$
We discuss the J/psi suppression in the framework of multiple collision models. From the analysis of the Pb-Pb NA50 data we conclude that the strength of the absorption has increased, but we find no clear evidence for the formation of the…
The production of charmonia is investigated for heavy-ion collisions from SPS to RHIC energies. Our approach incorporates two sources of $J/\Psi$ yield: (i) a direct contribution arising from early (hard) parton-parton collisions, subject…
Thirty years ago, Matsui and Satz proposed the $J/\psi$ destruction as a signal of a Quark Gluon Plasma (QGP) formation, due to the Debye screening between the pair c-cbar. At the light of the recent experimental data, I review the…
We consider $J/\psi$ photoproduction in ion--ion ultraperipheral collisions (UPCs) at the LHC and RHIC in the coherent and incoherent quasielastic channels with and without accompanying forward neutron emission and analyze the role of…
Stringent physical constraints relate the $J/\psi$ produced at a given transverse momentum $p_T$ to the Bjorken-$x$ of the initial gluons. We present a new approach which takes them into account in order to explicitely investigate the…
The transverse momentum (pt) dependence of J/psi production in heavy ion collisions is investigated in a transport model with both initial production and continuous regeneration of charmonia. The competition between the two production…
We discuss the exclusive $J/\psi$ photoproduction process, as measured recently at LHCb, as a means of constraining and ultimately determining the low $x$ and low $Q$ gluon PDF. The scale dependence of the theoretical prediction for this…
We investigate the sensitivity of $J/\Psi$ production in proton-neutron and proton-deuteron collisions to charge symmetry violations in the parton distributions as well as to nuclear corrections. It is found that the effects of charge…
We propose an alternative way of looking at data on anomalous J/psi suppression. The proposed method is in principle equivalent to the one used by the NA50 Collaboration, but it permits to visualize separate contributions of individual…
We calculate the cross section of J/psi inclusive production in lepton-nucleon deep-inelastic scattering via the weak charged current within the factorization formalism of nonrelativistic quantum chromodynamics. The hadronic system produced…
We investigate the reaction gamma+p -> V+p, with V denoting a Phi or a J/Psi meson, within the scope of perturbative QCD, treating the proton as a quark-diquark system. Our predictions extrapolate the existing forward differential…
We point out that data on the onset of anomalous J/psi suppression as a function of nucleon numbers A and B could provide information on the dynamics of nuclear interactions. In particular the models of anomalous J/psi suppression by…
We calculate the photoproduction of double $J/\psi$ ($\Upsilon$) to leading order based on the nonrelativistic quantum chromodynamics factorization framework at the Large Hadron Collider with forward proton tagging. The numerical results of…
Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and RHIC…
A reexamination of hadronic comover scattering indicates that this mechanism cannot explain the observed $\psi$ suppression in Pb+Pb interactions. The possibility of quark-gluon plasma formation is therefore considered.
Nuclear gluon densities are of great importance to the physics of relativistic heavy ion collisions, in particular, in assessing the origin of $J/\psi$-suppression. We describe our attempts to distinguish various models of the gluonic…
The nuclear overlap zone in non-central relativistic heavy ion collisions is azimuthally very asymmetric. By varying the angle between the axes of deformation and the transverse direction of the pair momenta, the suppression of $J/\Psi$ and…
A significant excess of J/$\psi$ yield at very low transverse momentum ($p_T < 0.3$ GeV/c) was observed by the ALICE and STAR collaborations in peripheral A+A collisions, which points to evidence of coherent photoproduction of J/$\psi$ in…
The quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to constrain the…
We discuss the photoproduction of $\Upsilon$ and $J/\psi$ at high energy $\bar{p}p$, $pp$ and heavy ion colliders. We predict large rates in $\bar{p}p$ interactions at the Fermilab Tevatron %and in heavy-ion interactions at the CERN LHC.…