Heavy Quarkonia in Lattice QCD with Anisotropic Highly Improved Staggered Quarks

具有各向异性高度改进交错夸克的晶格 QCD 中的重夸克尼亚

• 批准号: 2309946
• 负责人: Alexei Bazavov
• 金额: $ 30万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309946&HistoricalAwards=false
• 关键词: Heavy; Quarkonia; Lattice; QCD; Anisotropic

The strong force binds elementary particles called quarks into protons and neutrons and the latter into atomic nuclei that are the fundamental building blocks of the matter observed in the Universe at all scales. These strong interactions of the elementary constituents are successfully described by Quantum Chromodynamics (QCD) - a quantum field theory developed in the course of 20th century. Predictions of QCD have been verified with amazing experimental precision. Under normal conditions isolated quarks are not observed - they are confined in composite objects like protons and neutrons. However, when strongly interacting matter is heated up to very high temperatures (about million times the temperature in the core of the Sun) or compressed to very high densities (the ones presumably achieved at the core of a neutron star), a novel phase of matter called Quark-Gluon Plasma (QGP) is formed. This project will study from first-principle QCD calculations the properties of QGP, in particular, how composite states of heavy quarks respond to the QGP medium and how the strong force behaves at very short distance scales (microscopy of QGP). These investigations will provide theoretical understanding and interpretation of the experimental results from the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory and Large Hadron Collider at the European Organization for Nuclear Research.Lattice QCD simulations are performed by Monte Carlo sampling the most probable configurations of fundamental fields on the four-dimensional space-time grid and computing physical observables on them. The physical information about heavy-quark bound states is encoded in their spectral functions. For reliable extraction of the spectral functions from Euclidean lattice correlation functions, the PI will develop a formalism of anisotropic Highly Improved Staggered Quarks (aHISQ), where the space-time grid is anisotropic with higher resolution in the temporal direction. The project will develop necessary algorithms and computer codes for lattice QCD simulations with dynamical aHISQ quarks and will generate a publicly available library of high-quality aHISQ ensembles of field configurations at various lattice spacings and anisotropies specifically for heavy quarkonia spectral function reconstruction. The heavy quarks will be included in the framework of Non-Relativistic QCD (NRQCD). Very high anisotropies combined with dynamical aHISQ quarks will pave the way to reliable extraction of the spectral functions with fully assessed statistical and systematic uncertainties. The PI will mentor doctorate students involved in the research as well as engage in public outreach activities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

强力将称为夸克的基本颗粒结合到质子和中子中，后者与原子核结合，这是所有尺度上在宇宙中观察到的物质的基本构件。这些基本成分的这些强烈相互作用通过量子染色体动力学（QCD）成功描述了20世纪发展的量子场理论。 QCD的预测已通过惊人的实验精度进行了验证。在正常条件下，未观察到孤立的夸克 - 它们被限制在质子和中子等复合物体中。但是，当强烈相互作用的物质被加热到非常高的温度（大约是太阳核心的温度的百万倍）或压缩到非常高的密度（大概是在中子恒星的核心中实现的）时，形成了一种新颖的物质阶段，称为Quark-Gluon Plasma（QGP）。该项目将从第一原则QCD计算QGP的特性，特别是重型夸克的复合状态如何响应QGP培养基以及强力在非常短的距离尺度（QGP的显微镜）中的表现。这些调查将提供理论上的理解和解释，对欧洲核研究组织的布鲁克黑文国家实验室的相对论重离子对撞机的实验结果和大型强子对撞机的实验结果。蒙特卡洛（Monte carlo）通过对四维式实时和计算的基本领域最可能的基本领域进行了最可能的配置来进行蒙特卡洛（Monte Carlo），以实现这些模拟。有关重Quark结合状态的物理信息在其光谱函数中编码。为了从欧几里得晶格相关函数中可靠地提取光谱函数，PI将发展各向异性高度改进的交错夸克（AHISQ）的形式主义，其中时空网格是各向异性的，在时间方向上有更高的分辨率。该项目将开发带有动态AHISQ QUARKS晶格QCD模拟的必要算法和计算机代码，并将在各种晶格间距和各向异性上为重型Quarkonia Spectral功能进行专门的各种晶格间距和各向异性，生成一个公开可用的高质量AHISQ集合库。重型夸克将包括在非相关QCD（NRQCD）的框架中。非常高的各向异性与动态AHISQ夸克结合使用，将为可靠的统计和系统不确定性提供可靠提取光谱函数的方式。 PI将指导参与研究的学生以及参与公共宣传活动。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来获得支持。