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arXiv 1603.01952hep-phnucl-th
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热密夸克物质输运系数的估算

Estimating transport coefficients in hot and dense quark matter

Paramita Deb, Guru Prakash Kadam, Hiranmaya Mishra

摘要:

我们计算的输运系数,即剪切系数和体粘滞系数以及热的和致密的夸克物质的热导率。计算在Nambu-JonaLasinio(NJL)模型内进行。的输运系数的估计是使用准粒子的方法求解Boltzmann动力学方程内的弛豫时间近似。通过显协变的方法计算了跃迁率,得到了夸克-夸克和夸克-反夸克散射的热平均截面。对有限化学势也进行了计算。在模型参数范围内,剪切粘度与熵密度的比值在Mott转变温度处有一个最小值。当化学势为零时,体粘滞系数与熵密度之比随温度的升高而减小,在临界温度附近急剧减小,超过临界温度后,体粘滞系数与熵密度之比为零;当化学势为有限时,体粘滞系数与熵密度之比随温度的升高而缓慢增大,超过临界温度后,体粘滞系数与熵密度之比为零。导热系数在临界温度也有一个极小值。

英文摘要:

We compute the transport coefficients, namely, the coefficients of shear and bulk viscosity as well as thermal conductivity for hot and dense quark matter. The calculations are performed within the Nambu- Jona Lasinio (NJL) model. The estimation of the transport coefficients is made using a quasiparticle approach of solving the Boltzmann kinetic equation within the relaxation time approximation. The transition rates are calculated in a manifestly covariant manner to estimate the thermal-averaged cross sections for quark-quark and quark-antiquark scattering. The calculations are performed for finite chemical potential also. Within the parameters of the model, the ratio of shear viscosity to entropy density has a minimum at the Mott transition temperature. At vanishing chemical potential, the ratio of bulk viscosity to entropy density, on the other hand, decreases with temperature with a sharp decrease near the critical temperature, and vanishes beyond it. At finite chemical potential, however, it increases slowly with temperature beyond the Mott temperature. The coefficient of thermal conductivity also shows a minimum at the critical temperature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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