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，一种新的物质形式被创造出来。通过晶格 QCD（第一性原理计算）来理解这种新物质非常重要。我们通过晶格QCD详细计算了夸克-胶子等离子体的剪切粘度，发现它非常小，并且物质几乎是完美的流体，这是实验所表明的。2）我们进行了上述计算，结果表明，体积-粘度非常小，但是正定。3）我们计算了禁闭和解禁闭阶段的夸克传播子。我们观察到，在限制阶段光谱不是正定的。夸克质量在限制和解除限制阶段是不同的。特别是在解除限制阶段，标准形式不起作用。4）在非常高的温度下，限制预计会被打破。为了理解这种现象，了解零温度下的限制机制很重要。为此，我们使用物理规范库仑规范，对颜色-库仑形式进行了数值计算。我们观察到限制力来自颜色库仑力，并且与 Fadddev-Popov 算子的特征值的行为有关。然而，特征值的温度行为与预期不同，即特征值在零附近的凝聚并没有消失。限制/解除限制转换非常重要。5）我们在 CELTLL 上开发了莱迪思 QCD 代码，这是一种新的高性能计算机体系结构。

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

Development of QCD-code on a CELL Machine

在 CELL 机器上开发 QCD 代码

• 发表时间: 2007
• 期刊: PoS LATTICE2007
• 作者: J.;Wei;Jaume Garriga and Takahiro Tanaka;H. Okamoto;Nathalie Deruelle;Masaru Shibata;H. Higaki;Atsushi Nakamura;Masahiro Nakashima;Atsushi Nakamura;H. Okamoto;Masaki Satoh;J. Wei;Hiroaki Wada;David Langlois;R.Takai;Chul-Moon Yoo;M. Adachi;S. Motoki
• 通讯作者: S. Motoki

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