通过相对论重离子碰撞研究中子皮和核对称能  

Determine the neutron skin thickness and nuclear symmetry energy at relativistic heavy ion collisions

作　　者：徐浩洁 王福强 XU Hao-Jie;WANG Fu-Qiang(School of Science,Huzhou University,Huzhou 313000,China;Strong-Coupling Physics International Research Laboratory(SPiRL),Huzhou UniversityHuzhou 313000,China;Department of Physics and Astronomy,Purdue University,West Lafayette IN 47907,USA)

机构地区：[1]湖州师范学院理学院,湖州313000 [2]湖州师范学院强耦合物理国际实验室,湖州313000 [3]普渡大学物理与天文系,美国西拉法叶47907

出　　处：《中国科学：物理学、力学、天文学》2024年第9期57-70,共14页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:12275082,12035006,12075085)资助项目。

摘　　要：相对论重离子碰撞的末态产物的分布可以非常直接地反映碰撞的初态几何,然而这些效应通常被淹没在热密物质演化的各种不确定性中.相对论同量异位素核碰撞是把^(96)Ru核(钌-96)和^(96)Zr(锆-96)核加速到接近光速进行的碰撞.由于其高度相似性,我们可以通过对比两个系统观测量的差异来消除热密物质演化带来的不确定性,从而达到探寻相应核密度分布的细节,因此同量异位素核碰撞是测量核结构的绝佳平台.本文简要综述了核结构对同量异位素核碰撞的重要影响,并讨论在此类核碰撞中测量中子皮及核对称能的一些方法.Nuclear symmetry energy and its density dependence are crucial for understanding of the masses and drip lines of neutronrich nuclei and the equation of state of nuclear and neutron star matter. Neutron skin thickness has traditionally been measured using low-energy electron and hadron scatterings from nuclei. In this brief review, we summarize recent progress in determining the neutron skin thickness and the nuclear symmetry energy density slope parameter in an unconventional way by using relativistic isobar(^(96)Ru+^(96)Ru and^(96)Zr+^(96)Zr) collisions. The final-state observables of relativistic heavy ion collisions can reflect the initial collision geometry of the collision, but in a way sensitive to the final-state evolution. Since the effects of final-state evolution are nearly identical between isobar collisions, the differences in the final-state observables directly reflect the nuclear structure difference of the colliding nuclei. Thus, isobar collisions provide an excellent platform for measuring the nuclear structure independent of unresolved details of the strong interaction. We start by laying out the importance of nuclear structure in relativistic isobar collisions. We then present and discuss several isobar ratio observables to measure the neutron skin thicknesses of the isobars and the nuclear symmetry energy density slope parameter, namely,ratios in the charged hadron multiplicity, mean transverse momentum, net charge multiplicity, dilepton photoproduction rate, and flow anisotropies.

关 键 词：相对论重离子碰撞 同量异位素核 中子皮 核对称能 

分 类 号：O571.6[理学—粒子物理与原子核物理]