Development of Lattice QCD Simulation System on PC Cluster

量子色动力学（QCD）是夸克和胶子的理论。Wilson提出的晶格QCD的数值模拟是研究QCD最有效、最可靠的方法。由于计算机的快速发展，即价格的降低和速度的快速提高，使得在PC集群上进行晶格QCO模拟成为可能，许多基础物理/核物理研究人员对该方法感兴趣。虽然许多基本粒子物理和核物理理论物理学家对晶格QCD有很好的理解，但由于需要大量的数值模拟技术知识和较长的时间，对他们来说进行晶格QCD模拟是很困难的。在这个项目中，我们开发了一个开源代码的点阵QCD在Fortran 90。该代码称为Fortran90中的Lattice Tool Kit (LTK f90)，可以在Fortran90中的模块https://:/nio-mon.riise.hiroshirna-u.ac.jp/~LTK/Thanks中找到，我们可以编写与算法相似且易于理解的程序。由于Fortran90有时依赖于机器的编译器，我们准备了一份用户手册，也可以在上面的网站上获得。我们使用MPI（消息传递接口）来并行化代码，然后可以进行大晶格大小的模拟。MPI是最有效的并行编程方式，但对于非专业人员来说并不容易，而且带有MPI的代码在非MPI编译器下无法执行。我们现在正在开发LTK的HPF（高性能Fortran）版本。

QCD (Quantum Chromo-Dynamics) is the theory of quarks and gluons. Numerical simulations of lattice QCD formulated by Wilson are the most powerful and reliable method to study QCD. Due to the fast development of computers, I.e., the price becomes lower and the speed increases rapidly, the lattice QCO simulations on PC cluster become possible, many researchers in elementary/nuclear physics are interested in the method.Although many theoretical physicists in elementary particle and nuclear physics understand lattice QCD well, it is difficult for them to perform lattice QCD simulations, since it required many knowledge of numerical simulation techniques and long time. In this project wehlave developed an open source code of lattice QCD in Fortran 90. The code is called Lattice Tool Kit in Fortran90 (LTK f90) and can be found athttp://nio-mon.riise.hiroshirna-u.ac.jp/~LTK/Thanks to the module in Fortran90, we can write programs which are similar to the algorithm and easy to understand. Because Fortran90 sometime depends on the compiler of the machine, we have prepared a user-manual, which can also be obtained on the above web.We use MPI (Message Passing Interface) to parallelize the code,and then large lattice size simulations are possible.MPI is the most effective way for parallel programming, but it is not so easy for non-specialist, and also a code with MPI can not be executed under non-MPI compiler. We are now developing a HPF (High Performance Fortran) version of LTK.