Related papers: Evidence for a J/psi-ppbar Pauli Strong Coupling ?
The charmonium dissociation by mesons in relativistic heavy-ion reactions is analyzed within the Regge approach. It is shown that the inclusion of the initial and final state interactions in the dissociation of J/Psi to bar{D}* D* close to…
We reanalyze the dissociation process of the $J/\psi$ by $\pi$ and $\rho$ mesons into $D + \bar{D}$, $D^* + \bar{D}$, $D + \bar{D}^*$, and $D^* + \bar{D}^*$ within a meson exchange model. In addition to the dissociation mechanisms…
In heavy ion collisions after the quark-gluon plasma there is a hadronic gas phase. Using effective Lagrangians we study the interactions of charmed mesons which lead to $J/\psi$ production and absorption in this gas. We update and extend…
The discoveries of the hidden-charm $P_c$ pentaquarks by the LHCb Collaboration have been not confirmed by other experiments yet. It is desirable to investigate the feasibility of observing them in other experiments. We present an…
We have studied the J/psi suppression in 158 GeV/c Pb+Pb collisions at CERN SPS. J/psi production is assumed to be a two step process, (i) formation of c bar{c} pair, which is accurately calculable in QCD and (ii) formation of J/psi meson…
Associated production of $J/\psi$ and a $\gamma$ has recently been proposed as clean probe of the gluon distribution. The same mechanism can be used to probe the polarized gluon content of the proton in polarized proton-proton collisions.…
A colorless c-cbar dipole emerging from a heavy ion collision and developing the charmonium wave function can be broken-up by final state interactions (FSI) propagating through the hot medium created in the collision. We single out two…
We study the $\Lambda_{b}\rightarrow J/\psi K^{0}\Lambda$ reaction considering both the $K^{0}\Lambda$ interaction with its coupled channels and the $J/\psi\Lambda$ interaction. The latter is described by taking into account the fact that…
To understand the reliability of the charmonia suppression as a signature of the Quark-Gluon Plasma formation in nucleus-nucleus collisions it is important first to understand the details of the production of J/psi and psi' in pA…
We present a new measurement of the e+e- -> J/psi ccbar cross section where the ccbar pair can fragment either into charmed hadrons or a charmonium state. In the former case the J/psi and a charmed hadron are reconstructed, while the latter…
Using A Multi-Phase Transport (AMPT) model, we study J/psi production from interactions between charm and anti-charm quarks in initial parton phase and between D and Dbar mesons in final hadron phase of relativistic heavy ion collisions at…
We present a microscopic calculation of the breakup cross sections of $J/\psi$ and $\psi'$ on pions and nucleons as a function of the kinetic energy. These cross sections are used for the investigation of the $J/\psi$ to continuum and…
We report on charmonium measurements [J/psi(1S), psi'(2S), and chi_c(1P)] in p+p collisions at sqrt(s)=200 GeV. We find that the fraction of J/psi coming from the feed-down decay of psi' and chi_c in the midrapidity region ($|\eta|<0.35$)…
Recent results on charmonia decays at BES/BEPC are reported, including the observation of psi'-->K_S K_L, psi'--> Vector + Tensor for the measurement of the relative phase between the strong and electromagnetic decays of psi' and a test of…
The observed features of $\psi'$ to $J/\psi$ suppression in $pA$ and nucleus-nucleus collisions can be explained in terms of a two-component absorption model. For the hard component of the absorption due to the interaction of the produced…
The role of power corrections and higher Fock-state contributions to exclusive charmonium decays will be discussed. It will be argued that the J/Psi (Psi') decays into baryon-antibaryon pairs are dominated by the valence Fock-state…
We present measurements of the polarization of the $ J/\psi $ produced in 800-GeV proton interactions with a copper target. Polarization of the $ J/\psi $ is sensitive to the $ c \bar{c} $ production and hadronization processes. A…
The recent data for E866 experiment on the x_F dependence for charmonium suppression in pA collisions at 800 GeV are analyzed using a time- and energy-dependent preformed charmonium absorption cross section \sigma_{abs}^\psi(\tau,\sqrt{s}).…
In this note we present an evaluation of the couplings JD(*)D(*) and JD(*)D(*)pi in the Constituent Quark Model. These couplings are a crucial ingredient in the calculation of cross sections for the processes pi J/psi -> D(*)Dbar(*), an…
$J/\psi$ production cross section considering the contributions of both color-singlet and color-octet $c\bar c$ channels is calculated. The result is used to study the suppression of $J/\psi$ in nuclear collisions. With absorption cross…