Research on the quark-gluon plasma and its probes

夸克-胶子等离子体及其探针研究

基本信息

批准号：
09640350
负责人：
MATSUI Tetsuo
金额：
$ 1.54万
依托单位：
The University of Tokyo (1999)Kyoto University (1997-1998)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Research was conducted on signals of the quark-gluon plasma formation in ultrarelativistic nucleus-nucleus collision, focusing on the dynamical process of the chiral phase transition and J/ ψ suppression by the onset of Debye screening in the plasma.As a quark-gluon plasma cools down, a phase transition is expected to occur associated with spontaneous break-down of the (approximate) chiral symmetry. We studied the dynamics of the order parameter of this phase transition using the linear sigma model, an effective theory of QCD. We adopted the framework of the functional Schrodinger equation with variational ansatz for the wave-functional. We generalized the classical plane-wave solutions of the non-linear sigma model (the Anselm-Ryskin solutions) to include the effect of the quantum fluctuations by the method. We formulated a mean-field theory of the interacting quantum meson fields based on the Hatree-Bogoliubov method in the many-body problem and showed that our non-covariant functional Schrodinger equations can be transformed to a manifestly covariant form of Klein-Gordon type equations. Our solutions of collective isospin rotating modes of interacting meson fields was also extended to finite temperature using the Gaussian density matrices and the damping time of the modes was estimated by the linear response theory.The problem of J/ ψ suppression as a signal of the quark-gluon plasma was studied focusing on the interplay of a coherent effect such as the plasma screening of the binding potential of heavy quark and its antiparticle and an incoherent effect such as the scattering with individual plasma

对超相对论核-核碰撞中夸克-胶子等离子体形成的信号进行了研究，重点关注手性相变的动力学过程以及等离子体中德拜屏蔽开始引起的J/ψ抑制。冷却下来，预计会发生与（近似）手性对称性自发破坏相关的相变，我们使用线性西格玛研究了该相变的有序参数的动力学。模型，一种有效的 QCD 理论。我们采用了波泛函的泛函薛定谔方程的框架，我们将非线性 sigma 模型的经典平面波解（Anselm-Ryskin 解）推广到包括。我们基于多体问题中的 Hatree-Bogoliubov 方法制定了相互作用量子介子场的平均场理论，并证明了我们的非协变。函数薛定谔方程可以转化为克莱因-戈登型方程的明显协变形式，我们对相互作用介子场的集体同位旋旋转模式的解也可以使用高斯密度矩阵扩展到有限温度，并且模式的阻尼时间通过下式估计。线性响应理论。研究了 J/ψ 抑制作为夸克-胶子等离子体信号的问题，重点是相干效应的相互作用，例如重离子结合势的等离子体筛选夸克及其反粒子以及非相干效应，例如单个等离子体的散射