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arXiv 0704.3707hep-phnucl-th
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大密度和温度下物质状态方程的软化:手征对称性恢复与夸克解除禁闭

Softening of the equation of state of matter at large densities and temperatures: chiral symmetry restoration vs. quark deconfinement

Luca Bonanno, Alessandro Drago, Andrea Lavagno

摘要:

我们讨论了两个模型,用于描述在大密度和中间温度的物质的行为。在这两种模型中,由于新的自由度的出现,状态方程发生软化。第一种是强子模型,其中的软化是由于手征对称性恢复。在第二个模型中,软化与混合相中夸克团的形成有关。我们表明,这两种模型都允许显着的软化,但在第一种情况下,体积模量主要取决于密度,而在混合相模型中,它也很大程度上取决于温度。我们还表明,由于存在两个保守的电荷,重子和同位旋的混合相的体积模量是不为零。只有在密度和温度很小的区域内,不可压缩性才变得极小。最后将我们的结果与最近对中能重离子碰撞的分析进行了比较。

英文摘要:

We discuss two models for describing the behavior of matter at large densities and intermediate temperatures. In both models a softening of the equation of state takes place due to the appearance of new degrees of freedom. The first is a hadronic model in which the softening is due to chiral symmetry restoration. In the second model the softening is associated with the formation of clusters of quarks in the mixed phase. We show that both models allow a significant softening but, in the first case the bulk modulus is mainly dependent on the density, while in the mixed phase model it also strongly depends on the temperature. We also show that the bulk modulus is not vanishing in the mixed phase due to the presence of two conserved charges, the baryon and the isospin one. Only in a small region of densities and temperatures the incompressibility becomes extremely small. Finally we compare our results with recent analysis of heavy ion collisions at intermediate energies.

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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