Equation of State at Finite Density from Imaginary Chemical Potential
Equation of State at Finite Density from Imaginary Chemical Potential
复制标题
虚化学势的有限密度状态方程
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Nakamura
中科院分区：
文献类型：
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作者：
T. Takaishi;P. Forcrand;A. Nakamura
我们使用虚化学势进行了两次风味 QCD 模拟，并测量了作为虚化学势和温度 T ε [0.83Tc,2Tc] 函数的压力高达 4 阶的导数。对于温度 T ≥ Tc，这些导数通过 μ/T 约 μ = 0 的泰勒级数进行拟合。仅限于 4 阶的拟合无法很好地描述所有温度下的数据，这表明我们对 6 阶贡献很敏感。同样，对于温度 Tc ≤ T ≤ 1.05Tc，六阶拟合失败，这表明需要八阶项。因此，与 μ = 0 时泰勒系数的直接测量相比，我们的方法可能具有计算优势。在温度 T ≤ Tc 时，我们用强子共振气体模拟拟合我们的数据。在 T 和 0.95Tc 处拟合开始失败。使用我们的拟合，我们还重建了作为真实夸克和同位旋化学势函数的状态方程。
We perform two flavor QCD simulations with an imaginary chemical potential and measure derivatives of the pressure up to 4th order as a function of the imaginary chemical potential and the temperature T ∈ [0.83Tc,2Tc]. For temperatures T ≥ Tc, these derivatives are fitted by a Taylor series in μ/T about μ = 0. A fit limited to 4th order describes the data poorly at all temperatures, showing that we are sensitive to 6th order contributions. Similarly, a 6th order fit fails for temperatures Tc ≤ T ≤ 1.05Tc, showing the need for 8th order terms. Thus, our method may offer a computational advantage over the direct measurement of Taylor coefficients at μ = 0. At temperatures T ≤ Tc, we fit our data with a hadron resonance gas ansatz. The fit starts to fail at T & 0.95Tc. Using our fits, we also reconstruct the equation of state as a function of real quark and isospin chemical potentials.