158A GeV/c Pb+Pb碰撞可能有QGP的一旁证

A Circumstantial Evidence for the Possible Production of QGP in the 158A GeV/c Central Pb+Pb Collisions

用不含QGP假设的强子和弦级联模型 (JPCIAE) ,研究了CERNWA98实验组新近发表的 1 58AGeV cPb +Pb中心碰撞中直接光子和π0 粒子的横动量分布 :两者的理论结果均一致的低于实验值 .联系到JPCIAE能成功解释无直接光子超出确切迹象的WA80和WA93对 2 0 0AGeV cS +Au中心碰撞测量得出的结果 :因而为 1 58AGeV cPb

Hadron and string cascade model (JPCIAE),based on the hypothesis without introducing the quark gluon plasma(QGP),is employed to study the direct photon and π 0 transverse momentum distributions for central 208Pb+ 208Pb collisions at 158A GeV/c. The theoretical results of transverse momentum distribution for both the direct photon and the π 0 particle are lower than the data of WA98 experiment. However,JPCIAE model can ever explain successfully the results of WA80 and WA93 experiments of central S+Au collisions at 200A GeV/c where there is no evidence of direct photon excess. Having considered the results of WA80 and WA93 experiments can be explained but WA98's can't,that might provide a circumstantial evidence for the possible production of QGP in the high energy central Pb+Pb collisions.