Sigma and hydrodynamic modes along the critical line
Sigma and hydrodynamic modes along the critical line
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DOI：
10.1103/physrevd.70.014016
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发表时间：
2004-02
影响因子：
5
通讯作者：
H. Fujii;M. Ohtani
中科院分区：
文献类型：
--
作者：
H. Fujii;M. Ohtani
假设在温度、重子数化学势和夸克质量的空间中有一个双味QCD的三临界点，在Ginzburg-Landau方法和Nambu-char21Jona-Lasinio模型中，我们研究了相关软模在临界线上的变化。沿着手征临界线的有序密度是标量密度，而标量、重子数和能量密度的线性组合成为沿着有限夸克质量的临界线的适当有序密度。结果表明，在三临界点，临界本征模从标量密度的Sigma类涨落转变为流体动力学模式，在那里我们有两个有序密度，即标量密度和重子数与能量密度的线性组合。我们认为，具有流体动力学性质的临界本征模的出现是守恒密度的发散极化率的逻辑结果。
Assuming a tricritical point of two-flavor QCD in the space of temperature, baryon number chemical potential, and quark mass, we study the change of the associated soft mode along the critical line within the Ginzburg-Landau approach and the Nambu\char21{}Jona-Lasinio model. The ordering density along the chiral critical line is the scalar density whereas a linear combination of the scalar, baryon number, and energy densities becomes the proper ordering density along the critical line with finite quark masses. It is shown that the critical eigenmode shifts from the sigma-like fluctuation of the scalar density to a hydrodynamic mode at the tricritical point, where we have two ordering densities, the scalar density and a linear combination of the baryon number and energy densities. We argue that the appearance of the critical eigenmode with hydrodynamic character is a logical consequence of divergent susceptibilities of the conserved densities.