Resonant Few-Body Systems from the Lattice

晶格共振少体系统

• 批准号: 2012289
• 负责人: Michael Doering
• 金额: $ 36万
• 依托单位: George Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2012289&HistoricalAwards=false
• 关键词: Resonant; Few; Body; Systems; Lattice

Strong forces are responsible for the formation of matter as we know it, but the precise mechanism of how this occurs remain a mystery. Strong forces bind nucleons together in atomic nuclei, but they also lead to the emergence of resonant phenomena at higher energies that are studied, e.g., at the Thomas Jefferson National Accelerator Facility (JLab). The experimental and theoretical quest for resonances to understand the strong force focuses on few-body systems and their dynamics. This project aims at closing the gap between theoretical calculations on few-body systems, called lattice QCD, and phenomenology. The main technical challenge addressed in this proposal concerns the problem that these calculations are performed in a small cubic volume instead of infinite space, and how to remove the corresponding artifacts so that lattice QCD can be compared to Nature. Deviations of these predictions from measurements are hints for new physics. The project also aims to conceptually improve the analysis of three-body data from experiment. The PI will in parallel develop simulations of simple quantum mechanical systems to illustrate the undergraduate and graduate curriculum along the lines of standard textbooks to help develop a diverse, globally competitive STEM workforce.The theory underlying the strong force, Quantum Chromodynamics (QCD), can be calculated using Lattice QCD. However, finite-volume effects for the case of three particles are poorly understood. This project aims to further develop three-body methods to enable the extrapolation of Lattice QCD results to the physical world and to help answer fundamental questions regarding QCD predictions for the properties of excited mesons and baryons. For this, the principle of unitarity, related to the conservation of probability in nuclear reactions, can be efficiently used as the guiding principle, and can be extended to the three- or more particle sector. In this project, methods will be conceptually upgraded to be applied to emblematic resonances. To highlight one, the Roper resonance has been under investigation for decades due to its unusually light mass and its debated nature as radial excitation of the nucleon or hadronic molecule. Furthermore, there is no clear signal for it in ab-initio lattice QCD calculations. The focus of this project is to quantify the finite-volume effects to solve this puzzle. Other lines of investigation address axial resonances that, in their three-body dynamics, resemble the supposed exotic mesons – a new type of particle sought for at JLab and other experiments.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.

强大的力量是我们所知道的物质形成的原因，但是这种发生的确切机制仍然是一个谜。强力在原子核中结合核能，但它们也导致了在较高的能量（例如，在托马斯·杰斐逊国家加速器设施（JLAB））中出现共鸣现象的出现。对共鸣的实验和理论追求了解强大的力量侧重于几体系统及其动态。该项目旨在缩小几体系统（称为晶格QCD）和现象学上的理论计算之间的差距。该提案中提出的主要技术挑战是涉及这些计算以小三次体积而不是无限空间执行的问题，以及如何去除相应的伪像，以便可以将晶格QCD与自然进行比较。这些预测与测量的偏差是新物理学的提示。该项目还旨在从概念上改善对实验的三体数据的分析。 PI将在平行地开发简单量子机械系统的模拟中，以说明沿标准教科书线的基础和研究生课程，以帮助开发多样性，全球竞争性的STEM劳动力。但是，对三个粒子的情况很少了解。该项目旨在进一步开发三体方法，以使晶格QCD结果推出到物理世界中，并帮助回答有关QCD关于极端介子和男爵属性的QCD预测的基本问题。为此，与核反应中概率的保护有关的统一原则可以有效地用作指导原理，并且可以扩展到三个或更多的粒子部门。在此项目中，将在概念上升级以应用于象征性共振。为了强调一个，由于其异常轻的质量和核分子的径向兴奋性，roper共振一直在研究数十年。此外，在Ab-Initio晶格QCD计算中没有明确的信号。该项目的重点是量化有限体积效应来解决这个难题。其他投资线解决了轴向共振，在其三体动力学中，类似于预期的异国情调的介子 - 在JLAB和其他实验中，一种新型的粒子气味。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来获得的支持。

项目成果

Multi-particle systems on the lattice and chiral extrapolations: a brief review

• DOI: 10.1140/epjs/s11734-021-00146-5
• 发表时间: 2021-02
• 期刊: The European Physical Journal Special Topics
• 作者: M. Mai;M. Döring;A. Rusetsky

Three-Body Dynamics of the a1(1260) Resonance from Lattice QCD

晶格 QCD 的 a1(1260) 共振的三体动力学

• DOI: 10.1103/physrevlett.127.222001
• 发表时间: 2021
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Mai, Maxim;Alexandru, Andrei;Brett, Ruairí;Culver, Chris;Döring, Michael;Lee, Frank X.;Sadasivan, Daniel
• 通讯作者: Sadasivan, Daniel

Particle-dimer approach for the Roper resonance in a finite volume

• DOI: 10.1007/jhep04(2023)100
• 发表时间: 2022-12
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: D. Severt;M. Mai;U. Meissner

Finite-volume energy spectrum of the K−K−K− system

• DOI: 10.1103/physrevd.102.114523
• 发表时间: 2020-09
• 期刊: Physical Review D
• 影响因子: 5
• 作者: A. Alexandru;R. Brett;C. Culver;M. Döring;D. Guo;F. Lee;M. Mai

Towards a theory of hadron resonances

• DOI: 10.1016/j.physrep.2022.11.005
• 发表时间: 2022-06
• 期刊: Physics Reports
• 作者: M. Mai;U. Meissner;C. Urbach