论文标题
各向异性流的非线性模式耦合的精确测试通过等速器的高能量碰撞
Precision tests of the nonlinear mode coupling of anisotropic flow via high-energy collisions of isobars
论文作者
论文摘要
有关扩展流体动力学的有价值信息可以从此类系统对其初始几何形状的扰动的响应中推断出来。 We apply this technique in high-energy $^{96}$Ru+$^{96}$Ru and $^{96}$Zr+$^{96}$Zr collisions to scrutinize the expansion dynamics of the quark-gluon plasma, where the initial geometry perturbations are sourced by the differences in deformations and radial profiles between $^{96}$Ru and $^{96} $ zr，集体响应是通过两种碰撞系统之间各向异性流量$ v_n $的变化来捕获的。使用传输模型，我们分析了低阶流量谐波之间的非线性耦合$ v_2 $和$ v_3 $与高阶流量谐波$ v_4 $和$ v_5 $之间的耦合，预计将扩展为$ v_ {4 \ mathrm {nl}}} V_2V_3 $，随着一个人从$^{96} $ ru+$^{96} $ ru移动到$^{96} $^{96} $ zr+$^{96} $ zr Systems。我们发现，这些缩放关系是有效到高精度的：$ v_ {4 \ mathrm {nl}} $和$ v_ {5 \ mathrm {nl}} $的变化，这是由于Quadrupole formortation，Octupole Formustration，Octupole Formustration，cotify Skin and cop ucififie $ coudy $ ucoud $ us $ p $ ^ $ ^ $ ^ $ ^ 4} $。然而，百分比级别的偏差大于预期的实验不确定性，并且可以测量。因此，具有不同核结构的等速箱的碰撞是隔离夸克 - 格鲁隆等离子体扩展中微妙的非线性效应的独特工具，否则在单个碰撞系统中无法访问。
Valuable information on the dynamics of expanding fluids can be inferred from the response of such systems to perturbations in their initial geometry. We apply this technique in high-energy $^{96}$Ru+$^{96}$Ru and $^{96}$Zr+$^{96}$Zr collisions to scrutinize the expansion dynamics of the quark-gluon plasma, where the initial geometry perturbations are sourced by the differences in deformations and radial profiles between $^{96}$Ru and $^{96}$Zr, and the collective response is captured by the change in anisotropic flow $V_n$ between the two collision systems. Using a transport model, we analyze how the nonlinear coupling between lower-order flow harmonics $V_2$ and $V_3$ to the higher-order flow harmonics $V_4$ and $V_5$, expected to scale as $V_{4\mathrm{NL}}=χ_4 V_2^2$ and $V_{5\mathrm{NL}}=χ_5 V_2V_3$, gets modified as one moves from $^{96}$Ru+$^{96}$Ru to $^{96}$Zr+$^{96}$Zr systems. We find that these scaling relations are valid to high precision: variations of order 20\% in $V_{4\mathrm{NL}}$ and $V_{5\mathrm{NL}}$ due to differences in quadrupole deformation, octupole deformation, and nuclear skin modify $χ_{4}$ and $χ_5$ by about 1--2\%. Percent-level deviations are however larger than the expected experimental uncertainties and could be measured. Therefore, collisions of isobars with different nuclear structures are a unique tool to isolate subtle nonlinear effects in the expansion of the quark-gluon plasma that would be otherwise impossible to access in a single collision system.
