Research on the quark-gluon plasma and its probes

夸克-胶子等离子体及其探针研究

• 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
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640350/
• 关键词: quark-gluon plasma; ultra-relativistic nucleus-nucleus; chiral phase transition; J; ψ suppression; カイラル相転移; Ψ抑圧; クォーク・グルオン・プラズマ; 相対論的重イオン反応

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

研究了超相对论核-核碰撞中夸克-胶子等离子体形成的信号，着重讨论了手征相变的动力学过程和等离子体中德拜屏蔽的出现对J/π的抑制.当夸克-胶子等离子体冷却时，将发生与手征对称性自发破缺有关的相变.我们利用QCD的有效理论--线性σ模型研究了这种相变的序参量动力学。对于波泛函，我们采用了泛函薛定谔方程和变分不等式的框架。我们推广了非线性sigma模型的经典平面波解（Anselm-Ryskin解），使其包含量子涨落的影响.基于多体问题中的Hatree-Bogoliubov方法建立了相互作用量子介子场的平均场理论，并证明了非协变泛函Schrodinger方程可以转化为显协变形式的Klein-Gordon型方程.利用高斯密度矩阵将相互作用介子场集体同位旋旋转模的解推广到有限温度，并利用线性响应理论估计了各模的阻尼时间，讨论了J/π作为夸克信号的抑制问题。研究了胶子等离子体中相干效应的相互作用，如胶子等离子体对重夸克及其反粒子结合势的屏蔽以及不相干效应，例如与单个等离子体的散射

项目成果

Y. Tsue, D. Vantherin, T. Matsui: "Lifetime of Collective isospin rotation of a quantum meson field"Physical Review D. (in press). (2000)

Y. Tsue、D. Vantherin、T. Matsui：“量子介子场集体同位旋旋转的寿命”物理评论 D.（出版中）。

T. Matsui: "Quark Matter '97: theoretical overview"Nuclear Physics A. 638. 19c-33c (1998)

T.松井：“Quark Matter 97：理论概述”核物理 A. 638. 19c-33c (1998)

Y. Tsue, D. Vautherin and T. Matsui: "Lifetime of collective isospin rotations of a quantum meson field"Phys. Rev. D. (in press). (2000)

Y. Tsue、D. Vautherin 和 T. Matsui：“量子介子场集体同位旋旋转的寿命”Phys。

Y. Tsue, D. Vautherin, T. Matsui: "Lifetime of collective isospin rotation of a quantum meson fields"Phys. Rey. D. (in press). (2000)

Y. Tsue、D. Vautherin、T. Matsui：“量子介子场集体同位旋旋转的寿命”Phys。