AI 中文总结
RHIC束流能量扫描计划旨在研究QCD相图，STAR探测器的固定靶碰撞扩展了测量范围。通过测量轻强子谱，用爆炸波模型研究动力学冻结温度等，展示了四个碰撞能量的结果，为重离子碰撞模型和QCD物质状态方程提供重要输入。
AI 中文摘要
相对论重离子对撞机（RHIC）束流能量扫描计划的主要物理目标之一是研究量子色动力学（QCD）相图，特别是夸克-胶子等离子体与强子物质之间的相变。束流能量扫描第一阶段研究了质心能量（\(\sqrt{s_{NN}}\)）从7.7到62.4 GeV的金离子-金离子碰撞。束流能量扫描第二阶段在几个重要方面扩展了这些测量，其中之一是增加了一个固定靶计划，将碰撞能量降低到3.0 GeV（或重子化学势\(\mu_B\)提高到720 MeV）。STAR的固定靶碰撞允许对QCD相图进行更广泛的扫描，进入QCD临界点可能所在的重要区域，以及由密集重子物质主导的区域。固定靶计划中的一项关键测量是最轻强子（\(\pi^{\pm}\)，\(K^{\pm}\)，p）的谱作为横向动量、快度和碰撞中心度的函数。从\(p_T\)谱中，使用爆炸波模型研究动力学冻结温度和膨胀物质的表面速度。这些结果为这些能量下的重离子碰撞模型提供了重要输入，并有助于约束QCD物质的状态方程。这里展示了固定靶范围内四个碰撞能量（\(\sqrt{s_{NN}} = 3.2\)，3.5，3.9和4.5 GeV）的结果。
英文摘要
One of the main physics goals of the Beam Energy Scan program at RHIC is to study the QCD phase diagram, specifically around the phase transition between the quark-gluon plasma and hadronic matter. Beam Energy Scan Phase-I studied Au+Au collisions from center-of-mass energy ($\sqrt{s_{NN}}$) of 7.7 to 62.4 GeV. Beam Energy Scan Phase-II extended these measurements in several important ways, one of which was the addition of a fixed-target program that pushed the collision energy down to 3.0 GeV (or baryon chemical potential, $μ_B$, up to 720 MeV). Fixed-target collisions at STAR allow for a more extensive scanning of the QCD phase diagram to an important region where the QCD critical point may lie, and to a region dominated by dense baryonic matter. One key measurement in the fixed-target program is the spectrum of the lightest hadrons ($π^{\pm}$, $K^{\pm}$, p) as a function of transverse momentum, rapidity, and collision centrality. From the $p_T$ spectra, a blast-wave model is used to study the temperature at kinetic freeze-out and the surface velocity of the expanding matter. These results provide important input to models of heavy ion collisions at these energies, and can help constrain the equation of state of QCD matter. Here, results are shown for four collision energies in the fixed-target range: $\sqrt{s_{NN}} = 3.2$, 3.5, 3.9, and 4.5 GeV.
CommentsConference Proceedings: The 22nd International Conference on Strangeness in Quark Matter (SQM 2026). 3 Figures. 4 Pages. Submitted on behalf of the STAR collaboration
Journal refJournal of Subatomic Particles and Cosmology 6 (2026) 100484
DOI：10.1016/j.jspc.2026.100484
