标题： 在200A GeV/c能级下S + Au中心碰撞中的包容性和直接光子 显示英文标题

标题： Inclusive and Direct Photons in S + Au Central Collisions at 200A GeV/c

摘要： 一个基于LUND弦模型，特别是PYTHIA事件生成器的强子和弦级联模型，JPCIAE，被用于研究200A GeV S + Au中心碰撞中包括光子和直接光子的产生。 该模型考虑了来自部分子QCD散射过程的光子产生、强子末态相互作用以及强子衰变，并对它们进行了统一处理。 JPCIAE模型的结果成功再现了WA93低p_T包括光子分布的数据以及WA80直接光子横向动量依赖的上限数据。 研究了不同衰变通道对直接光子和包括光子的光子产生。 我们还讨论了部分子QCD散射和强子末态相互作用对直接光子产生的影响。 显示英文摘要

摘要： A hadron and string cascade model, JPCIAE, which is based on LUND string model, PYTHIA event generator especially, is used to study both inclusive photon production and direct photon production in 200A GeV S + Au central collisions. The model takes into account the photon production from the partonic QCD scattering process, the hadronic final-state interaction, and the hadronic decay and deals with them consistently. The results of JPCIAE model reproduce successfully both the WA93 data of low p_T inclusive photon distribution and the WA80 data of transverse momentum dependent upper limit of direct photon. The photon production from different decay channels is investigated for both direct and inclusive photons. We have discussed the effects of the partonic QCD scattering and the hadronic final-state interaction on direct photon production as well.