Parton collisional effect on the conversion of geometry eccentricities into momentum anisotropies in relativistic heavy-ion collisions

Elliptic and triangular flow of heavy flavor in heavy-ion collisions

We investigate the elliptic and the triangular flow of heavy mesons in ultrarelativistic heavy-ion collisions at RHIC and the LHC. The dynamics of heavy quarks is coupled to the locally thermalized and fluid dynamically evolving quark-gluon plasma. The elliptic flow of $D$ mesons and the centrality dependence measured at the LHC is well reproduced for purely collisional and bremsstrahlung interactions. Due to the event-by-event fluctuating initial conditions from the EPOS2 model, the $D$ meson triangular flow is predicted to be nonzero at $\sqrt{s}=200$ GeV and $\sqrt{s}=2.76$ TeV. We study th…

Nearly isentropic flow at sizeable $η/s$

Non-linearities in the harmonic spectra of hadron-nucleus and nucleus-nucleus collisions provide evidence for the dynamical response to azimuthal spatial eccentricities. Here, we demonstrate within the framework of transport theory that even the mildest interaction correction to a picture of free-streaming particle distributions, namely the inclusion of one perturbatively weak interaction ("one-hit dynamics"), will generically give rise to all observed linear and non-linear structures. We further argue that transport theory naturally accounts within the range of its validity for realistic sign…

重离子碰撞初态几何的$v_2$涨落约束

Constraints from $v_2$ fluctuations for the initial state geometry of heavy-ion collisions

精确计算表征超相对论性重离子碰撞中粒子产生的动量空间各向异性的系数系列$v_n$作为中心性的函数的能力被广泛认为是描述体物质演化的流体动力学的胜利。然而，流体动力学建模的一个关键因素是物质的初始空间分布，这是由一个尚未完全理解的平衡过程产生的。因此，对这种初始状态几何形状直接敏感的测量对于预平衡动力学的约束模型具有很高的价值。最近，它已经表明，这样的测量确实是可能的，在事件的归一化$v_n$分布的事件概率分布作为中心性的函数，这是独立于随后的流体动力学演化的细节的高精度，因此直接反映了空间偏心率的主要分布。我们提出了一个研究这个观察使用各种基于Glauber的模型，并认为实验数据放置非常严格的约束的初始分布的问题，并排除所有简单的基于Glauber的模型。

On nonlinearity in hydrodynamic response to the initial geometry in relativistic heavy-ion collisions

In the context of event-by-event hydrodynamic description, we analyze the implications of two models characterized by distinct initial conditions. The initial energy density of the first model adopts a Gaussian-type distribution, while those of the second one are features by high energy peripheral tubes. We calibrate the initial conditions of both models so that their initial probability distribution of eccentricity are mostly identical. Subsequently, the resultant scaled probability distributions of collective flow and the correlations between flow harmonic and eccentricity coefficients are i…

Phenomenological predictions of 3+1d anisotropic hydrodynamics

We make phenomenological predictions for particle spectra and elliptic flow in heavy-ion collisions using 3+1d anisotropic hydrodynamics (aHydro) including the effects of both shear and bulk viscosities. The dynamical equations necessary are derived by taking moments of the Boltzmann equation allowing for three distinct (diagonal) momentum-space anisotropy parameters. The formulation is based on relaxation-time approximation for the collisional kernel and a lattice-QCD-based equation of state. Evolving the system to late times, we calculate particle production using THERMINATOR 2, modified to …

重离子碰撞中的各向异性标度函数：对“超中心流疑难”的启示及对输运系数与核形变的约束

Anisotropy Scaling Functions in Heavy-Ion Collisions: Insights into the `Ultra-Central Flow Puzzle' and Constraints on Transport Coefficients and Nuclear Deformation

本研究通过不同能量、不同核种重离子碰撞的各向异性系数测量推导各向异性标度函数，整合多类测量结果，揭示初态与介质性质对各向异性的影响，为超中心流疑难提供新见解并约束输运系数与核形变。

利用多相传输模型研究相对论重离子碰撞中的非线性集体动力学

Investigation of Nonlinear Collective Dynamics in Relativistic Heavy-Ion Collisions Using A Multi-Phase Transport Model

研究利用多相传输模型探讨了重离子碰撞中非线性响应系数χ_{4,22}的微观起源及演化过程，揭示其与初始态几何相关性及集体膨胀的动力学关系。