CSR外靶重离子碰撞实验全同粒子HBT关联模拟研究

In according to the theory of intensity interferometry, we plan to research on the identical particle correlations (HBT) for pions and protons in heavyion collisions at the CSR external-target experiments,in order to obtain the beam energy exciting function of the spatial length and temporal scale of the particle emission source. The the single particle space-momentum correlation effect to the two-particle correlation results will be researched by analyzing the transverse momenta dependence of the correlation radius at freeze-out. The dependence of the correlation radius on the final particle multiplicity, the initial participating nucleons, the binary collisions, and the velocity of collective expansion will be researched also. And finally, the investigation of femtoscopic measurements for identical particle correlations at CSR external-target experiments will be theoretical obtained..Under the framework of quantum molecule dynamics (QMD), the physical mechanism of the space-momentum effect at CSR will be investigated. It will also be studied to clear the correct relation between the transverse correlation radius and the partial source with the strong space-momentum correlation. To understand the transformation mechanism of the initial space asymmetry of the source into the momentum asymmetry of the final state, the difference of the dependence of the correlation radius inside and outside of the reaction plane will be studied. Particularly, we also expect to obtain the sensitive signal of the equation of state at CSR, by our results of the two-particle correlation analysis, and provide the valuable suggestion for the CSR External-target Experiments (CEE) on two-particle correlation.measurements by GEANT simulations.

根据强度干涉学理论，对CSR外靶重离子碰撞实验分别进行介子和质子HBT全同粒子关联模拟研究，以期获得CSR能区源冻结空间尺度、源演化时间标度和源尺度束能激发函数；通过HBT半径随冻出粒子横动量的依赖关系，分析单粒子空间－动量关联效应对两粒子关联分析的影响；研究HBT关联对末态粒子多重性、初态参与者、两体碰撞和集体膨胀的响应，系统地给出CSR能区全同粒子关联观测的理论预言。.在量子分子动力学框架下，研究CSR能区空间-动量效应的物理机制；发现空间－动量关联发射源中关联半径与部分源的关系；分析关联半径在反应平面内、外随粒子横动量依赖关系的差异，理解初始源的空间非对称性向末态动量空间非对称性的转化机制；通过对CSR能区HBT模拟结果综合分析， 期望获得该能区核媒质态方程特性的敏感信息；通过GEANT仿真研究， 对CSR外靶实验谱仪CEE提出两粒子关联测量相关性能指标建议。

本项目以兰州重离子加速器冷却存储环上计划开展的外靶重离子碰撞实验为背景，利用微观输运模型模拟了多种碰撞体系、各种碰撞能量和不同初始条件下重离子碰撞事件，分析了模拟事件冻结源的单粒子谱和两粒子关联，较为系统地研究了高能重离子碰撞中事件的形状、冻结相空间、全同粒子关联、和集体流等重要问题，取得了有意义的研究结果。. 基于模拟事件末态粒子相空间分布，系统地进行末态单粒子谱和两粒子关联分析，研究了各向同性和各向异性集体流及其对两粒子关联的影响，获得发射源的寿命、空间尺度以及干涉学参数及其横动量依赖；分析了单粒子空间-动量关联和末态相互作用对干涉学结果的影响；探讨了该能区两粒子关联对同位旋效应、粒子的相干产生、集体流、核阻止和热化等物理的响应；探索了低温高密核媒质态方程。通过本项目研究，取得了预期的研究结果，达到了预期的研究目标。.