Spectral properties of massless and massive quarks coupled with massive boson at finite temperature
Spectral properties of massless and massive quarks coupled with massive boson at finite temperature
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DOI：
10.1103/physrevd.77.045034
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发表时间：
2007-10
影响因子：
5
通讯作者：
M. Kitazawa;T. Kunihiro;K. Mitsutani;Y. Nemoto
中科院分区：
文献类型：
--
作者：
M. Kitazawa;T. Kunihiro;K. Mitsutani;Y. Nemoto
在单环阶Yukawa模型中研究了有限温度下无质量夸克和有质量夸克与标量和伪标量玻色子耦合的性质。分析了谱函数的行为和传播子的极点结构作为温度T和夸克质量{m}_{f}$的函数。结果表明，对于有限的${m}_{f}$，谱函数的三峰结构在与玻色子质量相当的温度下形成，但随着${m}_{f}$变大，谱函数的三峰结构逐渐消失。在复能平面上，我们确定了与夸克的集体激发相对应的夸克传播子的三个极点。结果表明，当${m}_{f}$增加时，随着$T$变化而产生的三极轨迹在临界夸克质量处发生结构重排。这表明，在这一点上，集体夸克激发的物理内容发生了剧烈的变化。结果很好地解释了由大质量玻色子与夸克和热激发反夸克的空穴的共振散射引起的能级混合的概念。
We study the properties of massless and massive quarks coupled with a scalar and pseudoscalar boson at finite temperature in Yukawa models at the one-loop order. The behavior of the spectral function and the pole structure of the propagator are analyzed as functions of temperature $T$ and the quark mass ${m}_{f}$. It is shown that the three-peak structure of the spectral function found in a previous work for massless quarks is formed at temperatures comparable to the boson mass even for finite ${m}_{f}$, but gradually ceases to exist as ${m}_{f}$ becomes larger. We identify the three poles of the quark propagator corresponding to the collective excitations of the quark in the complex-energy plane. It is shown that the three trajectories made by the poles along with a variation of $T$ undergo a structural rearrangement at a critical quark mass when ${m}_{f}$ is increased. This suggests that the physics content of the collective quark excitations is changed in a drastic way at this point. The results are nicely accounted for with the notion of the level mixing induced by a resonant scattering of the massive boson with quarks and holes of thermally excited antiquarks.