Charmonium Dissociation and Recombination: Cold Effects
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 different effects on $J/\psi$ production, from SPS to LHC energies, distinguishing between Cold Nuclear Matter (CNM) and QGP effects. Different possibilities and explanations for the available experimental data are discussed. Model predictions for the arriving LHC data are also presented.
Charmonium dissociation and recombination at LHC: Revisiting comovers
Abstract We present our results on charmonium production at the Large Hadron Collider energies within the comover interaction model. The formalism includes both comover dissociation of J / ψ 's and possible secondary J / ψ production through recombination. The estimation of this effect is made without involving free parameters. The comover interaction model also incorporates an analytic treatment of initial-state nuclear shadowing. With these tools, the model successfully describes the centrality, transverse momentum and rapidity dependence of the experimental data from PbPb collisions at the LHC energy of s = 2.76 TeV . We present predictions for PbPb collisions at s = 5.5 TeV .
Shadowing and absorption effects on J/psi production in dA collisions
The authors study medium modifications of J/{psi} production in cold nuclear media in deuterium-nucleus collisions. They discuss several parameterizations of the modifications of the parton densities in the nucleus, known as shadowing, an initial-state effect. They also include absorption of the produced J/{psi} by nucleons, a final-state effect. Both spatially homogeneous and inhomogeneous shadowing and absorption are considered. They use the number of binary nucleon-nucleon collisions as a centrality measure. Results are presented for d+Au collisions at {radical}S{sub NN} = 200 GeV and for d+Pb collisions at {radical}S{sub NN} = 6.2 TeV. To contrast the centrality dependence in pA and dA collisions, they also present pPb results at {radical}S{sub NN} = 8.8 TeV.