Quark-Gluon Systems at Extreme Condition: International Collaboration for High Temperature and Density QCD

极端条件下的夸克-胶子系统：高温和密度 QCD 的国际合作

• 批准号: 17340080
• 负责人: NAKAMURA Atsushi
• 金额: $ 7.51万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17340080/
• 关键词: quarks; gluons; QGP; confining; QCD; クォーク・グルーオン・プラズマ; 格子ゲージ理論; シミュレーション; 輸送係数; 国際共同研究; 極限状態

1) At RBHIC, a new form of matter was created. It is important to understand this new matter by lattice QCD, the first-principle calculation. We calculated the shear viscosity of quark-gluon plasma in detail by lattice QCD and found that it is very small and the matter is almost perfect fluid, which is suggested by experiments.2) We proceed the above calculation, and showed that the bulk-viscosity is very small but positive definite.3) We calculated quark-propagators in both the confinement and the deconfinement phases. We observed that the spectrum is not positive definite in the confinement phase. Quark mass is difkent in the confinement and deconfmment phases. Especially in the deconfinement phase, a standard form does not work.4) At very high temperature, the confinement is expected to be broken. To understand this phenomena, it is important to understand the confinement mechanism at zero temperature. For this purpose, using the Coulomb gauge, which is the physical gauge, we calculated the color-Coulomb form numerically. We observed that the confinement force comes from the color-Coulomb force, and relates to the behavior of eigen values of the Fadddev-Popov operators. However, the temperature behavior of the eigen values is different from what was expected, ie., the condensation of the eigen-values near zero does not disappear. The confinement/deconfinement transition is very non-trivial.5) We developed a Lattice QCD code on the CELTLL which is a new architecture of high-performance computers.

1）在RBHIC，创建了一种新的物质形式。第一原则计算Lattice QCD了解这一新问题很重要。我们通过晶格QCD详细详细介绍了夸克 - 杜伦等离子体的剪切粘度，并发现它很小，而且物质几乎是完美的流体，这是通过实验提出的。2）我们进行上述计算，并表明散装效率很小，但很小的确定性。我们观察到频谱在禁闭阶段不是正定的。夸克质量在限制和解密阶段不同。尤其是在解密阶段，标准形式不起作用。4）在非常高的温度下，预计限制将被损坏。要了解这种现象，重要的是要了解零温度下的限制机制。为此，我们使用物理量规的库仑量规，我们通过数值计算了颜色库仑的形式。我们观察到限制力来自颜色库仑力，并与Faddddev-Popov算子的特征值的行为有关。但是，本征值的温度行为与预期的不同，即零接近元值的凝结不会消失。 5）我们在凯尔特尔（Celtll）上开发了一个晶格QCD代码，这是高性能计算机的新体系结构。

项目成果

I=1/2 Scalar and Axial Vector Mesons

I=1/2 标量和轴向矢量介子

• 发表时间: 2005
• 期刊: PoS LAT2005
• 作者: R. Sugahara;et. al.;Keiju Murata;A. Noda;M. Sekiguchi
• 通讯作者: M. Sekiguchi

格子QCD計算とハドロン・原子核物理

晶格 QCD 计算和强子/核物理

• 发表时间: 2008
• 作者: Hidenori Nomura;Misao Sasaki and Kazuhiro Yamamoto;中村純
• 通讯作者: 中村純

Lattice Study of Gluon Viscosities - A Step Towards RHIC Physics

胶子粘度的晶格研究 - 迈向 RHIC 物理的一步

• 发表时间: 2006
• 期刊: Acta Physica Polonica B 37
• 作者: A. Nakamura;S. Sakai
• 通讯作者: S. Sakai

Transport Coefficients of Gluon Plasma

胶子等离子体的传输系数

• 发表时间: 2005
• 期刊: Phys. Rev. Lett 94
• 作者: R. Sugahara;et. al.;A.Nakamura;Frederico Arroja;猪澤 健二;R. Sugahara;I. Pushkina;Atsushi Nakamura
• 通讯作者: Atsushi Nakamura

Quark propagators at finite temperature with the clover action

有限温度下的夸克传播体与三叶草作用

• 发表时间: 2006
• 期刊: PoS LAT2006
• 作者: Keisuke Izumi;Kazuya Koyama;Oriol Pujolas and Takahiro Tanaka;Y. Nakagawa;X.-P.Li;M.Ikegami;M. Hamada
• 通讯作者: M. Hamada