We study the excitation function of the low-lying charmonium state: $Psi$(3686) in $bar p$ Au collisions taking into account their in-medium propagation. The time evolution of the spectral functions of the charmonium state is studied with a BUU type transport model. We calculated the excitation function of $Psi$(3686) production and show that it is strongly effected by the medium. The energy regime will be available for the PANDA experiment.
In this paper we summarize our recent results for low energy associated charmonium production cross sections, using 1) crossing symmetry, and 2) an explicit hadronic model. These predictions are of relevance to the planned charmonium and charmonium hybrid production experiment PANDA at GSI.
The QCD mechanisms underlying the exclusive strong decays and hadronic production amplitudes of charmonium remain poorly understood, despite decades of study and an increasingly detaled body of experimental information. One set of hadronic channels of special interest are those that include baryon-antibaryon states. These are being investigated experimentally at BES and CLEO-c in terms of their baryon resonance content, and are also of interest for the future PANDA experiment, in which charmonium and charmonium hybrids will be produced in p-pbar annihilation in association with light mesons. In this paper we develop a simple initial-state light meson emission model of the near-threshold associated charmonium production processes p pbar -> pi0 ccbar, and evaluate the differential and total cross sections for these reactions in this model. (Here we consider the ccbar states eta_c, J/psi, psi, chi_0 and chi_1.) The predicted near-threshold cross section for p pbar -> pi0 J/psi is found to be numerically similar to two previous theoretical estimates, and is roughly comparable to the (sparse) existing data for this process. The theoretical charmonium angular distributions predicted by this model are far from isotropic, which may be of interest for PANDA detector design studies.
The phenomenological analysis of various characteristics of $J/psi$ and $D$ meson production in PbPb collisions at the center-of-mass energy 2.76 TeV per nucleon pair is presented. The data on momentum spectra and elliptic flow are reproduced by two-component model HYDJET++ including thermal and non-thermal charm production mechanisms. The significant part of $D$-mesons is found to be in a kinetic equilibrium with the created medium, while $J/psi$-mesons are characterized by earlier (as compared to light hadrons) freeze-out.
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 ($|eta|<0.35$) is 9.6+/-2.4% and 32+/-9%, respectively. We also report new, higher statistics p_T and rapidity dependencies of the J/psi yield via dielectron decay in the same midrapidity range and at forward rapidity (1.2<|eta|<2.4) via dimuon decay. These results are compared with measurements from other experiments and discussed in the context of current charmonium production models.
We consider forward inclusive production of several quarks in the high energy p-A collisions in the CGC formalism. For three particle production we provide a complete expression in terms of multipole scattering amplitudes on the nucleus and multi particle generalized TMDs of the proton. We then calculate all the terms that are not suppressed by the factor of the area in four particle production, and generalize this result up to terms of order $1/N_c^2$ for arbitrary number of produced particles. Our results include the contribution of quantum interference effects both in the final state radiation (HBT) and in the initial projectile wave function (Pauli blocking).