摘要
用建立在LUND模型特别是PYTHIA事件产生器基础上的描写极端相对论性核-核碰撞的强子和弦级联模型鳃─—JPCIAE研究了入射能量为200AGeV的pA和BA碰撞的最小偏畸事件中J／ψ的核压低．用两组J／ψ和强子形成时间合理的数值分别由正常模拟和类Glauber式模拟得到的J／ψ核压低因子可与NA38的相应pA和BA碰撞的数据相比较，但NA50Pb＋Ph碰撞的数则解释不了．另外，正常模拟和类Glauber式模拟间的差别，进而动力学模拟和Glauber理论间的差别不容忽略．仔细研究了强子形成时间对J／ψ核压低的敏感效应．结果还表明：对于J／ψ核压低来说，介子吸收在pA碰撞中也起作用犹如在BA碰撞中一样．
The proposed hadron and string cascade model, JPCIAE, for ultrarelativisticnucleus-nucleus collisions based on the LUND model and the PYTHIA eventgenerator especially, is used to inveshgate the J/ψ suppression due to the nuclearabsorption of a J/ψ in minimum bias pA and BA collisions at 200A GeV energy.With the different sets of reasonable formation bine for hadron and J/ψ the results ofJ/ψ suppression factor from both the usual scenario and the Glauber-like simulationsare comparable with all the NA38 PA and BA data, except the NA50 data of Ph +Pb collisions. However, the difference between the usual scenario and the Glauber-likesimulation, hence the difference betWeen the dynamical simulation and Glauber theory,can not be ignored. The sensitive effect of the hadron formation bine on the J/ψsuppression is studied in detail. The results seem to denote that for the J/ψ suppressionthe meson absorption plays a role in pA as well as in BA collisions.
出处
《高能物理与核物理》
CSCD
北大核心
1999年第5期489-495,共7页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金
核工业基金
关键词
强
弦
级联模型
核-核碰撞
J/Ψ核压低
hadron and string cascade model, JPCIAE event generator, minimum biasevent J/ψ suppression
