The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental da...The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental data and the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework of JPCIAE model and without retuning the model parameters. The predictions for collisions at the LHC energy were also given. We computed the participant nucleon distributions using different methods. It was found that the number of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may be inappropriate to use the charged particle pseudorapidity density per participant pair as a function of the number of participant nucleons for distinguishing various theoretical models.展开更多
A hadron and string cascade model, JPCIAE, together with the corresponding Monte Carlo event generator, has been employed in this paper to investigate further the charge fluctuations in Au+Au collisions at √ s nn = 1...A hadron and string cascade model, JPCIAE, together with the corresponding Monte Carlo event generator, has been employed in this paper to investigate further the charge fluctuations in Au+Au collisions at √ s nn = 130 GeV. The default JPCIAE calculations are in good agreement with PHENIX and STAR data. We found that the thermal predictions for the π gas, the resonance π gas and quark matter deviate, respectively. from the corresponding dynamical simulations from the JPCIAE model. The discrepancies were also found between the π charge fluctuations and the charge fluctuations of all species of hadrons. However the charge fluctuations for “π from ρ and ω decay” and for all the hadrons from resonance decay are close to each other, indicating the correlation between positively and negatively charged hardrons is not sensitive to the species of hardrons. This work shows further that it is questionable to use the charge fluctuations as a signature of QGP.展开更多
文摘The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental data and the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework of JPCIAE model and without retuning the model parameters. The predictions for collisions at the LHC energy were also given. We computed the participant nucleon distributions using different methods. It was found that the number of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may be inappropriate to use the charged particle pseudorapidity density per participant pair as a function of the number of participant nucleons for distinguishing various theoretical models.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 10075035).
文摘A hadron and string cascade model, JPCIAE, together with the corresponding Monte Carlo event generator, has been employed in this paper to investigate further the charge fluctuations in Au+Au collisions at √ s nn = 130 GeV. The default JPCIAE calculations are in good agreement with PHENIX and STAR data. We found that the thermal predictions for the π gas, the resonance π gas and quark matter deviate, respectively. from the corresponding dynamical simulations from the JPCIAE model. The discrepancies were also found between the π charge fluctuations and the charge fluctuations of all species of hadrons. However the charge fluctuations for “π from ρ and ω decay” and for all the hadrons from resonance decay are close to each other, indicating the correlation between positively and negatively charged hardrons is not sensitive to the species of hardrons. This work shows further that it is questionable to use the charge fluctuations as a signature of QGP.
