论文标题
在强磁场中的热QCD物质的动量及其附属运输系数
Momentum and its affiliated transport coefficients for a hot QCD matter in a strong magnetic field
论文作者
论文摘要
我们研究了各向异性对QCD物质（$η$）和散装（$ζ$）粘度的势头运输的影响。各向异性是由强磁场或优先膨胀引起的。这项研究有助于通过$η/s $和$ζ/s $和$ζ/s $（$ s $是熵密度）的流动性和位置，分别通过prandtl数字（PL）的声音衰减，雷诺数数量（RL）的流量性质（RL），以及动量和电荷差异之间的竞争。粘度是在准粒子模型中动力学理论的松弛时间近似中计算得出的。与各向同性培养基相比，$η$和$ζ$在磁场驱动（B驱动）各向异性中都增加了，与扩张驱动的各向异性的减少相反。 $η$在以前的情况下随温度的升高比在后一种情况下更快，而在以前的情况下，$ζ$随温度而降低，在后一种情况下，在特定温度下，它微不足道且降低。因此，粘度可以区分上述各向异性。因此，在以前的情况下，$η/s $会增强，在后一种情况下，它比各向同性的情况小。同样，$ζ/s $被放大，但随着温度在强磁场中的降低速度更快。与各向同性相比，在B诱导的各向异性中，PrandTL数量增加，并且在扩张引起的各向异性中降低。由于发现PL大于1，因此声音衰减受动量扩散控制。 B驱动的各向异性使雷诺数小于一个数字，而膨胀驱动的各向异性使其更大。比率（$ \fracη{s}/\ frac {σ_{\ rm el}} {t} $）在B驱动各向异性中得到扩增，而在扩展驱动的各向异性中会减少它。由于比率总是不止一个，因此动量扩散在电荷扩散上占上风。
We have studied the effects of anisotropies on the momentum transport in a QCD matter by shear ($η$) and bulk ($ζ$) viscosities. The anisotropies arise either by the strong magnetic field or by the preferential expansion. This study helps to understand the fluidity and location of transition point of matter through $η/s$ and $ζ/s$ ($s$ is entropy density), respectively, the sound attenuation through the Prandtl number (Pl), the nature of flow by the Reynolds number (Rl), and the competition between momentum and charge diffusions. The viscosities are calculated in the relaxation time approximation of kinetic theory within the quasiparticle model. Compared to isotropic medium, both $η$ and $ζ$ get increased in magnetic field-driven (B-driven) anisotropy, contrary to the decrease in expansion-driven anisotropy. $η$ increases with temperature faster in former case than in latter case whereas $ζ$ in former case decreases with temperature and in latter case, it is meagre and diminishes at a specific temperature. So the viscosities can distinguish aforesaid anisotropies. Thus, $η/s$ gets enhanced in former case and in latter case, it becomes smaller than isotropic one. Similarly $ζ/s$ gets amplified but decreases faster with the temperature in a strong magnetic field. The Prandtl number gets increased in B-induced anisotropy and gets decreased in expansion-induced anisotropy, compared to isotropic one. Since, Pl is found larger than 1, the sound attenuation is governed by momentum diffusion. The B-driven anisotropy makes the Reynolds number smaller than one, whereas the expansion-driven anisotropy makes it larger. The ratio ($\fracη{s}/\frac{σ_{\rm el}}{T}$) gets amplified in B-driven anisotropy whereas it gets reduced in expansion-driven anisotropy. Since, the ratio is always more than one, the momentum diffusion prevails over the charge diffusion.
