TY  - INPR
A1  - Hammon, Nils
A1  - Gerland, Lars
A1  - Stöcker, Horst
A1  - Greiner, Walter
T1  - Charmonium suppression from purely geometrical effects
N2  - The extend to which geometrical effects contribute to the production and suppression of the J/psi and qq minijet pairs in general is investigated for high energy heavy ion collisions at SPS, RHIC and LHC energies. For the energy range under investigation, the geometrical e ects referred to are shadowing and anti-shadowing, respectively. Due to those effects, the parton distributions in nuclei deviate from the naive extrapolation from the free nucleon result; fA 6= AfN. The strength of the shadowing/anti-shadowing e ect increases with the mass number. Therefore it is interesting to see the di erence between cross sections for e.g. S+U vs. Pb+Pb at SPS. The recent NA50 results for the survival probability of produced J/psi s has attracted great attention and are often interpreted as a signature of a quark gluon plasma. This publication will present a fresh look on hard QCD e ects for the charmonium production level. It is shown that the apparent suppression of J/psi s must also be linked to the production process. Due to the uncertainty in the shadowing of gluons the suppression of charmonium states might not give reli- able information on a created plasma phase at the collider energies soon available. The consequences of shadowing e ects for the xF distribution of J/psi s at s = 20 GeV, s = 200 GeV and s = 6 TeV are calculated for some relevant combinations of nuclei, as well as the pT distribution of minijets at midrapidity for Nf = 4 in the final state.
KW  - Strahl
KW  - Kollisionen schwerer Ionen
KW  - QCD
KW  - Quanten-Chromodynamik
KW  - jet
KW  - heavy ion collisions
KW  - QCD
KW  - Quantum Chromodynamic
Y1  - 1998
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/3096
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-23040
ER  -