Three-Body Amplitudes from Lattice QCD

晶格 QCD 的三体振幅

• 批准号: 2310036
• 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: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310036&HistoricalAwards=false
• 关键词: Three; Body; Amplitudes; Lattice; QCD

Strong forces are responsible for the formation of known matter in the Universe, but the detailed mechanisms of how this happens remain a mystery. Strong forces bind nucleons (protons and neutrons) together in atomic nuclei, and the properties of the nucleons are studied at state-of-the-art accelerator facilities such as the Thomas Jefferson National Accelerator Facility. This project aims at closing the gap between experiment and theoretical calculations using lattice QCD. Due to current limitations of classical computers Lattice QCD calculations are performed in a small cubic volume instead of infinite space. This project provides the translation from the former to the latter, so that fundamental calculations of QCD can be compared to Nature. The PI and his students will focus on properties of systems involving three particles interacting with each other. To help develop a diverse, globally competitive STEM workforce, the outreach component is dedicated to developing material for computational aspects of quantum mechanics (QM) and animations of time-dependent QM problems. Finite-volume effects for the case of three particles are poorly understood. In this project, the PI and his students will develop and apply three-body methods to map 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 is efficiently used as the guiding principle to construct three- or more particle amplitudes. A conceptual upgrade of previous work concerns the introduction of more coupled channels and extensions to half-integer spin. Three-body dynamics is not only difficult on the theory but also on the phenomenology side. Therefore, three-body amplitudes in infinite volume will be developed and compared to experiment in a complementary effort, such as the Roper resonance and its multi-channel three-body dynamics, or the various decay channels of the A1(1260) axial meson. An extended analysis of new lattice QCD results from the GW group at two different pion masses is planned, that will allow to map out the chiral trajectory of the A1(1260) axial meson.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.

强大的力量负责宇宙中已知物质的形成，但是发生这种情况的详细机制仍然是一个谜。强力在原子核中结合核子（质子和中子），并在最新的加速器设施（例如Thomas Jefferson National Accelerator设施）中研究了核子的特性。该项目旨在使用晶格QCD缩小实验和理论计算之间的差距。由于经典计算机的当前局限性，晶格QCD计算是在一个小的立方容积而不是无限空间中进行的。该项目提供了从前者到后者的翻译，因此可以将QCD的基本计算与自然进行比较。 PI和他的学生将专注于涉及三个粒子相互作用的系统的属性。为了帮助发展多样化的全球竞争性STEM劳动力，外展组成部分致力于开发量子力学（QM）计算方面的材料和时间依赖于QM问题的动画。对于三个粒子的情况，有限体积效应知之甚少。在这个项目中，PI和他的学生将开发并应用三体方法将晶格QCD结果映射到物理世界中，并帮助回答有关QCD预测激动的梅森和巴里昂斯属性的基本问题。为此，单位性原理被有效用作构造三个或更多粒子幅度的指导原理。以前的工作的概念升级涉及将更多耦合的频道和扩展引入半数旋转。 三体动力学不仅在理论上很困难，而且在现象学方面也很困难。因此，将开发无限体积的三体幅度，并将其与互补工作中的实验进行比较，例如Roper共振及其多渠道三体动力学，或A1（1260）轴向Meson的各种衰减通道。计划对GW组的新晶格QCD进行扩展分析，以两个不同的pion群众的形式进行，这将允许绘制A1（1260）Axial Meson的手性轨迹。这项奖项反映了NSF的法定任务，并认为通过基金会的知识优点和宽阔的范围来评估NSF的法定任务。