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Chiral transition at high temperature and density and the σ-meson in nuclear medium

高温高密度手性转变与核介质中的σ介子

基本信息

批准号：
12640296
负责人：
KUNIHIRO Teiji
金额：
$ 1.22万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640296/
关键词：
Chiral Symmetry QCD Sigma meson Renormalization Group Transport Equations Chiral Transition 運動学的方程式 TDGL

项目摘要

(1) We have shown that partial restoration of chiral symmetry in nuclear medium induces a softening in the spectral function in the I = J = 0 channel, I.e., the σ-meson channel, irrespective of the linear or nonlinear representation of chiral symmetry; the softening can account for the experimental data by CHAOS group. The restoration of chiral symmetry is represented by a 4pi-NN vertex in the nonlinear chiral model that has been taken into account in the previous calculations in the literature.(2) Apart from 7r-nucleus reactions, we have shown (d, ^3He) and (d, t) reactions are interesting as a probe to explore partial restoration in heavy nuclei because they may produce the σ-mesic nuclei.(3) To examine whether the effective equation to describe the disoriented chiral condensate (DCC) is diffusion- or wave-equation type, we tried to deduce the time-dependent Ginzburg-Landau equation (TDGL) consistently by applying the derivative expansion. We have identified the divergence inherent in the derivative expansion due to the Landau damping a secular term familiar in the perturbation series of solutions of differential equations. Applying the so called the renormalization-group (RG) method, we have successfully obtained the resumed coefficients. It is underway to examine the resultant evolution equation has to do with TDGL.(4)Applying the RG method, we have given a unified and general theory for deriving kinetic and transport equations from the microscopic, equations including field theories.

(1)我们发现，在核介质中，手征对称性的部分恢复导致I=J=0通道，即σ-介子通道的谱函数软化，而与手征对称性的线性或非线性表示无关；这种软化可以解释混沌群的实验数据。(2)除了7r核反应外，(d，^3He)和(d，t)反应对于探索重核的部分恢复是很有意义的，因为它们可能产生σ-Mesic核。(3)为了检验描述无定向手性凝聚体的有效方程是扩散型还是波动方程型，我们尝试通过应用导数展开一致地推导出含时间的金兹堡-朗道方程。我们已经确定了导数展开式中由于朗道阻尼所固有的发散，朗道阻尼是微分方程解的摄动系列中常见的长期项。应用所谓的重整化群(RG)方法，我们成功地获得了恢复系数。(4)应用RG方法，我们给出了从包括场论在内的微观方程导出动力学方程和输运方程的统一和普遍的理论。