NRQCD Calculations of Heavy Quark Bound States: Focus on the Fine Structure

近年来，晶格量子色动力学（LQCD）取得了巨大的进步，从蝌蚪改进和改进的离散化1到包括多达三种动力学夸克的模拟。可以使用比以前认为的更粗糙的网格，将模拟成本降低多达10倍。除了降低模拟成本外，晶格模拟所需的时间也大大减少，最简单的计算现在可以在个人计算机上完成。最重要的是，现在可以进行高精度的LQCD计算，通常误差在1%或更小的数量级，可以用来测试QCD和预测实验结果。这些新技术的意义对于重夸克物理学特别重要。这个项目的重点是精确的LQCD计算的实验可测量的数量和扩展到更高的非相对论QCD（NRQCD）拉格朗日的v/c的权力的知识，可用于其他计算。该项目涉及与高精度量子色动力学（HPQCD）和英国量子色动力学（UKQCD）合作的成员的合作，并将专注于重夸克束缚态的NRQCD计算，特别是底夸克和底反夸克束缚态的Uppermeson的精细结构

In recent years great strides have been made in lattice quantum chromodynamics (LQCD) from tadpole improvement and improved discretizations1 to simulations that include up to three flavors of dynamical quarks. It is possible to use coarser lattices than previously thought, decreasing the cost of simulations by as much as a factor of 10. In addition to a decrease in the cost of simulations, the time required for lattice simulations has also significantly decreased, the simplest calculations can now be done on a personal computer. Most importantly, it is now possible to perform high precision LQCD calculations, often with errors on the order of 1% or less, that can be used to test QCD and to predict experimental results. The implications of these new techniques are of particular importance to heavy quark physics. This project focuses on precision LQCD calculations of experimentally measurable quantities and to extending to higher order in powers of v/c knowledge of the non-relativistic QCD (NRQCD) Lagrangian that can be used in other calculations. The project involves collaboration with members of the high precision quantum chromodynamics (HPQCD) and United Kingdom quantum chromodynamics (UKQCD) collaborations and will focus on NRQCD calculations of heavy quark bound states, in particular, on the fine structure of the Upsilon meson which is a bound state of a bottom quark and a bottom anti-quark