Numerical Simulation of Quark-Gluon Systems with Massvely Parallel Computer QCDPAX

大规模并行计算机QCDPAX对夸克-胶子系统的数值模拟

基本信息

批准号：
02402003
负责人：
IWASAKI Yoichi
金额：
$ 8.45万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02402003/
关键词：
massively parallel computer QCDPAX phase transition quark gluon hadron flavor lattice QCD ハ-ドウエアソフトウエア

项目摘要

In order to perform a large scale computation of lattice QCD with the massively parallel computer QCDPAX, which is constructed through the Grant-in-Aid for Specially Promoted Research in 1989, the environment for the development of QCDPAX-programs is further equipped by purchasing a workstation. On this environment, a high states tics Monte Carlo simulation of the gluon system at finite temperature is performed. First, fixing the lattice size in the temporal direction to be 4, two lattices with the spatial size of 12X12X24 and 24X24X36 are simulated. With the gauge coupling constant approximately at the phase transition point, 910, 000 and 710, 000 iterations are performed respectively. Then, increasing the temporal lattice size up to 6, lattices with the spatial size of 24X24X24 and 36X36X48 are simulated with 500, 000 and 1, 200, 000 interactions respectively. The latter simulation on the 36X36X48X6 lattice improves the previous computations to a large extent both in the size of the lattice and in the number of iterations. With this simulation, we can, for example, conclude that the value of the latent heat associated with the first order deconfining phase transition is about one half of a previous estimation on a small lattice for the case of the temporal lattice size 6. Secondly, we calculated the mass of hadrons on a 24X24X24X54 lattice. With a computation with higher precision than previous simulations, we find that the phenomenological mass formula works well for the quark mass down to about 1/3 of the strange quark mass. Thidly, we studied the confinement of quarks with varying the number of flavors and find that the confinement is lost for the flavor number larger than 7 even with the infinitely large gauge coupling constant.

为了利用1989年国家重点资助项目建设的大规模并行计算机QCDPAX进行大规模晶格QCD计算，通过购买一台计算机进一步配备了QCDPAX程序的开发环境。工作站。在此环境下，对有限温度下的胶子系统进行了高态抽动蒙特卡罗模拟。首先，固定时间方向的晶格尺寸为4，模拟空间尺寸为12X12X24和24X24X36的两个晶格。当规范耦合常数大约在相变点时，分别执行910、000和710、000次迭代。然后，将时间晶格尺寸增加到6，分别模拟空间尺寸为24X24X24和36X36X48的晶格，交互次数为500、000和1、200、000。后者在36X36X48X6晶格上的模拟无论在晶格尺寸还是迭代次数上都在很大程度上改进了之前的计算。例如，通过此模拟，我们可以得出结论，在时间晶格尺寸为 6 的情况下，与一阶去限制相变相关的潜热值约为之前对小晶格估计的一半。我们计算了 24X24X24X54 晶格上的强子质量。通过比之前模拟更高精度的计算，我们发现唯象质量公式对于低至奇夸克质量约 1/3 的夸克质量非常有效。第三，我们研究了不同风味数的夸克的限制，发现即使规范耦合常数无限大，风味数大于7时，限制也会消失。