Particle Physics and Lattice Gauge Theory

在过去的几年里，不同长度尺度上QCD真空的结构和禁闭机制一直是格点规范理论工作者激烈活动的焦点。格点规范理论为定量研究这种完全非微扰的现象提供了唯一可用的框架。该项目的研究领域包括：量子色动力学改进的作用;禁闭和量子色动力学真空物理;解除禁闭跃迁动力学;以及重离子碰撞中的夸克-胶子等离子体。 拟议的研究的一个目标是进一步发展系统的程序，连接的短距离（微扰）的长距离（非微扰）的限制制度在QCD真空。因此，它有助于直接从QCD中提取限制，这是理论粒子物理学的一个长期目标。它还导致建设的改进行动粗晶格精确确定弦张力和其他可观的减少离散化误差和计算工作量。该项目的第二个领域是解除禁闭动力学和重离子碰撞。相对论重离子对撞机（RHIC）最近的实验发现引起了广泛的兴趣。特别是，机制负责明显非常快速热化在所产生的强耦合夸克胶子等离子体以上解除禁闭仍然是一个悬而未决的问题和激烈的活动的焦点。非平衡场论的模拟方法必须发展，以妥善解决这些问题。在这个项目中，这种新的方法将通过详细的晶格研究进行调查，这是在以前的NSF支持下对去禁闭动力学模拟的自然延续。这个项目的更广泛的影响是，晶格规范理论的拟议研究涉及计算物理学中最先进的方法，这些方法在自然和生物科学和工程中具有广泛的适用性。因此，它为研究生和博士后研究员提供了此类技术的出色培训。例如，研究生从事以前资助的项目，由本研究员目前活跃在工程和生物研究项目。 该项目也可以作为，因为它在最近的过去，作为一个来源，在计算和统计物理的小型项目在高年级本科水平。实验发现（RHIC）和理论/计算物理之间的相互作用，在这个项目中也提供了说明性的材料，为主要研究员的推广活动，高中科学教师和学生。

Over the last several years the structure of the QCD vacuum over different length scales and the mechanisms of confinement have been the focus of intense activity among workers in lattice gauge theory. Lattice gauge theory provides the only available framework for the quantitative investigation of such entirely nonperturbative phenomena. Research in this project is in the areas of QCD improved actions; confinement and QCD vacuum physics; deconfinement transition dynamics; and the quark-gluon plasma in heavy ion collisions. A goal of the proposed research is to further develop systematic procedures that connect the short distance (perturbative) to the long distance (non-perturbative) confining regime in the QCD vacuum. It thus contributes towards directly extracting confinement from QCD, a long-standing goal of theoretical particle physics. It also leads to the construction of improved actions on coarser lattices for accurate determination of string tensions and other observables with reduced discretization errors and computational effort. The second area of the project is that of deconfinement dynamics and heavy ion collisions. The recent experimental discoveries at the Relativistic Heavy Ion Collider (RHIC) have generated wide interest. In particular, the mechanism responsible for the apparent very rapid thermalization in the resulting strongly-coupled quarkgluon plasma above deconfinement remains an unresolved question and the focus of intense activity. Simulation methods for non-equilibrium field theory must be developed to properly address such questions. In this project such novel methods are to be investigated by detailed lattice studies that are a natural continuation of simulations on deconfinement dynamics under previous NSF support.Broader Impacts of this project are that the proposed research in Lattice Gauge Theory involves state-of-the-art methods in Computational Physics that are of wide applicability in the Natural and Biological Sciences and Engineering. As such it provides excellent training in such techniques to graduate students and postdoctoral fellows. For example, graduate students engaged in previously funded projects by this investigator are currently active in engineering and biological research projects. The project can also serve, as it has in the recent past, as a source for mini projects in computation and statistical physics at the upper division undergraduate level. The interplay between experimental discoveries (RHIC) and theoretical/computational physics present in this project has also provided illustrative material for the principal investigator's outreach activities to high school science teachers and students.