Hadronic Excitations, Glueballs, and Scattering Phase Shifts using Lattice QCD with the Stochastic LapH Method

格点规范理论提供了研究强子激发谱的框架。因此，该项目将有助于解开量子色动力学中夸克禁闭和强子形成物理学的关键方面，强相互作用理论和自然界的基本力量之一。事实上，理解限制胶子的物理学是一个重要的智力挑战，并被公认为马萨诸塞州剑桥克莱数学研究所宣布的七个所谓的千年奖问题之一。激发强子共振的质量将使用时空晶格上夸克和胶子的马尔可夫链蒙特卡罗计算机模拟来评估。这些计算的结果是相关的几个正在进行的实验计划，如大厅B N* 计划和GREX实验在大厅D在托马斯杰斐逊国家加速器设施。值得一提的是，在过去，由于计算的限制，这种计算是在不切实际的大夸克质量下进行的。目前的项目继续发展一种新的方法，将关键的多强子算子纳入计算，以减少夸克质量接近其物理值。拟议的研究包括两名研究生的参与，可能还有一名或多名本科生，所以这个项目的更广泛的影响也涉及到晶格QCD领域未来研究人员的培训。学生们提供了一个独特的机会，学习和促进在核理论的前沿调查的重要路线。鉴于该项目的高性能方面，学生还将获得使用最先进的并行计算资源的基本技能。将通过在公众可访问的网页上张贴附有简化背景资料的结果，加强拟议活动的广泛影响。

Lattice gauge theory provides the framework to study the excited spectrum of hadrons. As such, this project will help unravel key aspects of the physics of quark confinement and hadron formation in quantum chromodynamics, the theory of the strong interactions and one of the fundamental forces of Nature. In fact, understanding the physics of confining gluons is an important intellectual challenge and was recognized as one of the seven so-called Millenium Prize problems announced by the Clay Mathematics Institute of Cambridge, Massachusetts. The masses of excited hadron resonances will be evaluated using Markov-chain Monte Carlo computer simulations of quarks and gluons on a space-time lattice. Results of these calculations are relevant to several ongoing experimental programs, such as the Hall B N* program and the GlueX experiment in Hall D at the Thomas Jefferson National Accelerator Facility. It is worth mentioning that in the past such calculations were performed with unrealistically large quark masses due to computational limitations. The current project continues the development of a new methodology to incorporate crucial multi-hadron operators into computations in order to reduce the quark masses to nearly their physical values.The proposed research incorporates the participation of two graduate students, and possibly one or more undergraduate students, so the broader impact of this project concerns also the training of future researchers in the field of lattice QCD. The students are provided with an unique opportunity to learn and contribute to an important line of inquiry at the forefront of nuclear theory. Given the high-performance aspects of this projects, students will also acquire essentials skills in the use of state-of-the-art parallel computing resources. The broader impacts of the proposed activities will be strengthened by posting results with simplified background information on publicly accessible web pages.