中国物理学会高能物理分会第十一届全国会员代表大会暨学术年会

中高能重离子碰撞中，集体流是研究夸克胶子等离子体的重要探针。本报告将着重介绍近期小系统及大系统中集体流测量结果。

Collective flow is a notable probe of studying the properties of the medium created in heavy ion collisions. Directed and elliptic flow, $v_1$ and $v_2$, are sensitive to the dynamics at the early stage of the system evolution and equation of state of the medium. The triangular flow $v_3$ provides complementary information on the initial geometry fluctuations and transport properties of the...

Longitudinal fluctuation which is the initial geometry fluctuates along pseudorapidity $\eta$, is found to be significantly important in understanding the full space time evolution of the fireball. Recent studies show that anisotropic flow coefficients are also sensitive to the shape of the nuclei, owing to the intrinsic deformation, while the deformation effect on the longitudinal physics is...

Relativistic heavy-ion collisions provide a unique opportunity to investigate properties of nuclear matter under extremely strong electromagnetic field. Using a heavy quark transport model that includes both collisional and radiative energy loss of heavy quarks, coupled to a (3+1)-dimensional viscous hydrodynamic model CLVisc, we study the initial longitudinal energy density distribution and...

Isobar collisions at RHIC provide unique opportunities to study the geometry and fluctuations raised from the deformation of the colliding nuclei. Using iEBE-VISHNU hybrid model, we predict $ac_2\{3\}$ ratios between these two collision systems and demonstrate that the ratios of $ac_2\{3\}$, as well as the ratios of the involving flow harmonics and event-plane correlations, are sensitive to...

RHIC-STAR的主要物理目标是研究夸克胶子等离子体（QGP）的性质及QCD相结构。格点QCD预言从强子到QGP相的相变存在一级相边界，而一级相边界终点是QCD临界点。定位一级相边界以及寻找相变临界点是当前STAR能量扫描实验的主要物理动机。集体流是研究QCD相结构的重要探针，本报告聚焦直接流v1,它是末态粒子在动量空间相对于反应平面方位角分布傅里叶展开式中的一阶系数，它描述重离子碰撞中产生粒子的侧向运动，携带碰撞早期的信息。由于QGP和强子相表现出不同的集体行为，因此直接流敏感于碰撞产生核物质的状态方程。 STAR已经完成了对撞能量$\sqrt{s_{NN}}$= 7.7-200 GeV的一期能量扫描计划（BES-I）。其中在$\sqrt{s_{NN}}$= 10-20...