Related papers: Are the $J/\psi$ and $\chi_c A$ Dependencies the S…
Mass differences of the charmonium mesons $\psi$(3770), $X$(3872), $\chi$(3929), $X$(3940), $\psi$(4040), $\psi$(4160), $X$(4259) and $\psi$(4415) have been studied. The analysis of data has shown, 5 of 7 mass differences with $\psi$(4415)…
Production of metastable charmonium states more massive than the $\psi(3685)$ is expected in models and could be the source of up to $50\%$ of the $\psi$ observed at large $p_T$ at the Tevatron.Narrow $2^{-+},2^{--} c\bar{c}$ are predicted…
The measured ratios $R(x,A_1/A_2)$ for $J/\Psi$, $\Psi'$ and $\mu^+\mu^-$ production on two different targets $A_1, A_2$ as a function of the fractional momentum $x$ of the final state are well fit with a very simple functional form having…
Recent results on K$^0_{\rm S}$ and hyperon production in Pb-Pb collisions at 40 and 158 $A$ GeV/$c$ beam momentum from the NA57 experiment at CERN SPS are presented. Yields and ratios are compared with those measured by the NA49…
The prompt production of the charmonium $\chi_{c1}$ and $\chi_{c2}$ mesons has been studied in proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=7$ TeV. The $\chi_c$ mesons are identified through…
A study of prompt and non-prompt J/$\psi$ production as a function of charged-particle multiplicity in inelastic proton--proton (pp) collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV based on calculations using the PYTHIA8 Monte…
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of $3{\rm\ fb}^{-1}$ collected at centre-of-mass energies of 7 and 8…
The inclusive production of charmonium mesons in B meson decay has been studied in a 20.3 fb$^{-1}$ data set collected by the BaBar experiment operating at the $\Upsilon(4S)$ resonance. Branching fractions have been measured for the…
The production of the ${}^1P_1$ charmonium state, $h_c$, at large-$p_T$ at the Tevatron is considered. The colour-octet contributions to this state are found to be dominant and give a reasonably large rate for the production of $h_c$. This…
In 2009, the BESIII experiment has collected about 225M $\jpsi$ and 106M $\psip$ samples, both of which are the world largest on-peak charmonium production. Based on these dataset, BESIII has made great effort on the study of the charmonium…
We find that available data on $J/\Psi$ photoproduction at $|t|{\ge}$1 GeV are energy independent over the range $22{\le}\sqrt{s}{\le}170$ GeV and show a very soft $t$ dependence. Through a systematic analysis of the data we detect a new…
We present measurements of the charmonium state $h_c(^1P_1)$ made with 106M $\psi'$ events collected by BESIII at BEPCII. Clear signals are observed for $\psi'\to\pi^0 h_c$ with and without the subsequent radiative decay…
We have analyzed the latest NA50 data on $J/\psi$ suppression in Pb+Pb collisions at CERN SPS. It is shown that a QCD based nuclear absorption model, where $J/\psi$'s are absorbed in nuclear medium could explain the latest NA50 data on the…
The production of charmonia in ultrarelativistic heavy-ion collisions is investigated including two sources. These are a primordial contribution coupled with various phases of dissociation, and a statistical coalescence of $c$ and $\bar{c}$…
The hypothesis of statistical production of J/psi mesons at hadronization is formulated and checked against experimental data. It explains in the natural way the observed scaling behavior of the J/psi to pion ratio at the CERN SPS energies.…
Coherence effects are important in the description of collisions with extended objects as nuclei. At fixed target energies and small x_F, the coherence length of the fluctuation containing the $c\bar c$ is small and the usual nuclear…
We report on forward-rapidity charmonium production in pp collisions at a center of mass energy $\sqrt{s} = 13$ TeV, as measured by ALICE at the LHC. Differential cross sections for both J/{\psi} and {\psi}(2S) are presented as a function…
We calculate the centrality dependence for coherent photoproduction of very low-$p_{T}$ $J/\psi$ at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies within the impact parameter dependent saturated color dipole…
The $N_c$-dependence of the vertices $PPP\gamma$, where $P$ is a pseudoscalar meson and $N_c$ is the number of colors, is analyzed with regard for the $N_c$-dependence of the quark charges. It is shown that the best processes for the…
The measurement of quarkonia production in relativistic heavy ion collisions provides a powerful tool for studying the properties of the hot and dense matter created in these collisions. To be really useful, however, such measurements must…