Thermal dilepton rate and electrical conductivity: An analysis of vector current correlation functions in quenched lattice QCD
Thermal dilepton rate and electrical conductivity: An analysis of vector current correlation functions in quenched lattice QCD
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DOI：
10.1103/physrevd.83.034504
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发表时间：
2010-12
影响因子：
5
通讯作者：
H. Ding;A. Francis;O. Kaczmarek;F. Karsch;E. Laermann;W. Soeldner
中科院分区：
文献类型：
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作者：
H. Ding;A. Francis;O. Kaczmarek;F. Karsch;E. Laermann;W. Soeldner
计算了QCD解禁相中轻价夸克的矢量电流关联函数。在T_≃为1.45℃的猝灭晶格QCD中，对最大尺寸为1283×48的晶格的四个截止值进行了计算。这允许在欧几里得时间间隔0.2≤τT≤0.5中执行关联函数的连续外推，其扩展到有限温度下可能的最大时间间隔，以优于1%的精度。在这段时间内，在所考察的温度范围内，我们发现对于无质量夸克，矢量关联函数与自由相关器的偏差从未超过9%。我们还确定了矢量介子谱函数的前两个非零热矩。第二个热矩与自由值的偏差小于7%。有了这些约束，我们继续提取矢量相关器的谱表示的信息，并讨论由此产生的结果对等离子体相的电导率和热双轻子率的影响。
We calculate the vector current correlation function for light valence quarks in the deconfined phase of QCD. The calculations have been performed in quenched lattice QCD at T ≃ 1.45Tc for four values of the lattice cut-off on lattices up to size 128 3 × 48. This allows to perform a continuum extrapolation of the correlation function in the Euclidean time interval 0.2 ≤ τT ≤ 0.5, which extends to the largest temporal separations possible at finite temperature, to better than 1% accuracy. In this interval, at the value of the temperature investigated, we find that the vector correlation function never deviates from the free correlator for massless quarks by more than 9%. We also determine the first two non-vanishing thermal moments of the vector meson spectral function. The second thermal moment deviates by less than 7% from the free value. With these constraints, we then proceed to extract information on the spectral representation of the vector correlator and discuss resulting consequences for the electrical conductivity and the thermal dilepton rate in the plasma phase.