用多流体方法模拟重子物质中的集体行为

用多种流体模拟致密重子物质中的集体性

Simulating collectivity in dense baryon matter with multiple fluids

提出三流体动力学模型 MUFFIN，通过模块化状态方程、双曲坐标和涨落初始条件模拟 RHIC 重离子碰撞，能再现 7.7–62.4 GeV 的快度与横动量谱，但理想流体假设导致椭圆流偏高。

Strange quark collectivity of $ϕ$ meson at RHIC

Based on A Multi-Phase Transport model, the elliptic flow $v_{2}$ of $ϕ$ mesons which is reconstructed from $K^{+}K^{-}$ at the Relativistic Heavy Ion Collider (RHIC) energy has been studied. The results show that reconstructed $v_{2}$ of $ϕ$ meson can keep the earlier information before $ϕ$ decays and it seems to obey the number of constituent quark scaling as other mesons and baryons. This result indicates that the $ϕ$ $v_2$ mostly reflects the parton level collectivity developed during the early stage of the collisions and the strange and light up/down quarks have similar collectivity prope…

A Study of the Properties of the QCD Phase Diagram in High-Energy Nuclear Collisions

With the aim of understanding the phase structure of nuclear matter created in high-energy nuclear collisions at finite baryon density, a beam energy scan program has been carried out at Relativistic Heavy Ion Collider (RHIC). In this mini-review, most recent experimental results on collectivity, criticality and heavy flavor productions will be discussed. The goal here is to establish the connection between current available data and future heavy-ion collision experiments in a high baryon density region.

Elliptic flow of $ϕ$ meson and strange quark collectivity at RHIC

Based on A Multi-Phase Transport (AMPT) model, we have studied the elliptic flow $v_{2}$ of $ϕ$ mesons from reconstructed $K^{+}K^{-}$ decay channel at the top Relativistic Heavy Ion Collider energy at Brookhaven National Laboratory. The dependences of $v_{2}$ on transverse momentum $p_T$ and collision centrality are presented and the rescattering effect of $ϕ$ mesons in the hadronic phase is also investigated. The results show that experimental measurement of $v_{2}$ for $ϕ$ mesons can retain the early collision information before $ϕ$ decays and that the $ϕ$ $v_2$ value obeys the constituent …

Evolution of Baryon-Free Matter Produced in Relativistic Heavy-Ion Collisions

A 3-fluid hydrodynamic model is introduced for simulating heavy-ion collisions at incident energies between few and about 200 AGeV. In addition to the two baryon-rich fluids of 2-fluid models, the new model incorporates a third, baryon-free (i.e. with zero net baryonic charge) fluid which is created in the mid-rapidity region. Its evolution is delayed due to a formation time $τ$, during which the baryon-free fluid neither thermalizes nor interacts with the baryon-rich fluids. After formation it thermalizes and starts to interact with the baryon-rich fluids. It is found that for $τ$=0 the inter…

Baryon Annihilation and Regeneration in Heavy Ion Collisions

The role of baryon-antibaryon annihilation during the hadronic stage of a relativistic heavy ion collision is explored by simulating the chemical evolution of a hadron gas. Beginning with a chemically equilibrated gas at an initial temperature of 170 MeV, the chemical composition of a representative hydrodynamic cell is followed throughout the hadronic stage. The cell's volume changes with time according to a parameterization that mimics a three-dimensional hydrodynamic expansion. The chemical evolution includes both annihilation and regeneration of baryons, consistent with detailed balance. D…