发表机构
Centro Multidisciplinario de Física, Vicerrectoría de Investigación, Universidad Mayor（大学主校，跨物理中心，研究副校长办公室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究有限重子不对称下各向异性热 QCD 介质粘性相关输运现象与可观测量，用弛豫时间近似法求解方程确定粘滞系数，发现膨胀诱导各向异性对粘滞系数及相关可观测量有显著影响。
AI 中文摘要
我们研究了在超相对论重离子碰撞初始阶段物质渐近膨胀导致的弱动量各向异性存在下，重子不对称热 QCD 介质粘性性质相关的输运现象与可观测量。通过普朗特数理解介质中的声衰减，通过雷诺数了解流的性质等。用弛豫时间近似方法求解相对论玻尔兹曼输运方程确定剪切和体粘滞系数。发现在有膨胀诱导各向异性时，无重子和重子不对称情形下剪切和体粘滞系数都减小，且重子不对称物质中粘滞系数更大，各向异性对两者影响显著，上述可观测量也受重子不对称介质中膨胀诱导各向异性显著调制。
英文摘要
We have studied the shear viscosity, bulk viscosity and associated observables of baryon asymmetric hot QCD medium subjected to weak momentum anisotropy induced by the asymptotic expansion of the medium during the early stages of ultrarelativistic heavy-ion collisions. The shear and bulk viscosities are evaluated by solving the relativistic Boltzmann transport equation within the relaxation time approximation in a kinetic theory framework. We have further analysed the Prandtl number, the Reynolds number, specific shear viscosity, and specific bulk viscosity, characterizing the sound attenuation, flow properties, fluidity, and conformal behavior, respectively. The interactions among the constituent partons are incorporated through the anisotropic quasiparticle distribution functions, with the medium characterized by finite temperature, momentum anisotropy and baryon asymmetry. Our analysis shows that both shear and bulk viscosities decrease with increasing anisotropy in both baryonless and baryon asymmetric media. In contrast, finite baryon asymmetry enhances both viscosities compared with their baryonless counterparts. The effects of expansion-induced anisotropy remain pronounced in both the baryonless and baryon asymmetric media, leading to substantial modifications of the associated viscous observables. These features are attributed primarily to the squeezing of the parton distribution functions caused by expansion-induced momentum anisotropy, together with the resulting modification of the partonic dispersion relations. Our results demonstrate that the expansion-induced anisotropy significantly influences the sound attenuation, flow characteristics, fluidity and conformal behavior of baryon asymmetric hot QCD medium, providing new insights into the viscous properties of the medium created in ultrarelativistic heavy-ion collisions.
Comments31 pages, 8 figures
