Fundamental Symmetries using Lattice QCD with the Gradient Flow

使用带有梯度流的格子 QCD 的基本对称性

• 批准号: 1913287
• 负责人: Andrea Shindler
• 金额: $ 27万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-15 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1913287&HistoricalAwards=false
• 关键词: Fundamental; Symmetries; using; Lattice; QCD

Even with the extraordinary success of the the Standard Model of Particle Physics (SM), certain phenomena observed in the Universe that have profound consequences to life as we know it, such as the matter-antimatter asymmetry, the hierarchy problem, and the existence of dark matter and dark energy, remain unexplained. Therefore any physical description of such phenomena requires a theory that goes beyond the Standard Model (BSM), while at the same time encompassing the Standard Model and its predictions related to ordinary matter. A physical quantity sensitive to the symmetry breaking responsible for the matter-antimatter asymmetry is the electric dipole moment (EDM) of particles such as neutron and proton. The PI will study the impact of theories beyond the Standard Model on the matter-antimatter asymmetry in the universe, calculating the electric dipole moments of protons and neutrons induced by such theories. In addition to investigating the role played by theories beyond the Standard Model on the observed matter-antimatter asymmetry in the universe, which is one of the biggest unanswered questions in particle and nuclear physics, the PI will mentor a student engaged in this research.This project uses a new method, based on the so-called gradient flow, for the determination of the Quantum Chromodynamics (QCD) component of key BSM matrix elements related to quark and strong theta-CP violations. This set of matrix elements impacts the understanding of electric dipole moments (EDMs) within nucleons and nuclei (a key signature of BSM physics) and their determination will lay the foundation for extraction of BSM observables from future low-energy, high-intensity experimental measurements. The use of the gradient flow will circumvent some of the big challenges posed by the determination of the above-mentioned matrix elements, introducing a new scale, the flow time, that will mitigate divergences present in the calculations. Additionally the gradient flow is perfectly suited to be adopted on QCD calculations on the lattice. Lattice QCD is, as today, the only robust and theoretically sound approach to non-perturbative QCD calculations. The new method the PI has developed is ideally suited to calculate all the CP-violating contributions to the EDM of nucleons and light nuclei. Most of the tools and technique developed in this project are alternative to traditional methods and can be easily applied to other matrix element calculations contributing to the study of dark matter candidates.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.

尽管粒子物理（SM）标准模型取得了非凡的成功，但在宇宙中观察到的某些对我们所知的生命具有深远影响的现象，例如物质-反物质不对称性、层次结构问题以及暗物质和暗能量的存在，仍然无法解释。因此，对此类现象的任何物理描述都需要一种超越标准模型（BSM）的理论，同时涵盖标准模型及其与普通物质相关的预测。对造成物质-反物质不对称性的对称破缺敏感的物理量是中子和质子等粒子的电偶极矩（EDM）。 PI将研究标准模型之外的理论对宇宙中物质-反物质不对称性的影响，计算由这些理论引起的质子和中子的电偶极矩。除了研究标准模型之外的理论对宇宙中观测到的物质-反物质不对称性（这是粒子和核物理中最大的未解答问题之一）所发挥的作用之外，PI还将指导一名从事这项研究的学生。该项目使用一种基于所谓梯度流的新方法来确定与夸克相关的关键BSM矩阵元素的量子色动力学（QCD）分量 和强烈的 theta-CP 违规。这组矩阵元素影响对核子和原子核内电偶极矩 (EDM)（BSM 物理学的关键特征）的理解，它们的确定将为从未来低能、高强度实验测量中提取 BSM 可观测量奠定基础。梯度流的使用将规避上述矩阵元素的确定所带来的一些重大挑战，引入新的尺度，即流动时间，这将减轻计算中存在的分歧。此外，梯度流非常适合用于晶格 QCD 计算。与今天一样，格子 QCD 是唯一稳健且理论上合理的非微扰 QCD 计算方法。 PI 开发的新方法非常适合计算核子和轻核 EDM 的所有 CP 破坏贡献。该项目中开发的大多数工具和技术都可以替代传统方法，并且可以轻松应用于有助于暗物质候选者研究的其他矩阵元计算。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Short flow-time coefficients of CP -violating operators

• DOI: 10.1103/physrevd.102.034509
• 发表时间: 2020-05
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Matthew D. Rizik;C. Monahan;A. Shindler

One-loop matching for quark dipole operators in a gradient-flow scheme

• DOI: 10.1007/jhep04(2022)050
• 发表时间: 2021-11
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: E. Mereghetti;C. Monahan;Matthew D. Rizik;A. Shindler;P. Stoffer

A novel nonperturbative renormalization scheme for local operators

一种新颖的局部算子非扰动重整化方案

• DOI: 10.22323/1.396.0155
• 发表时间: 2022
• 期刊: The 38th International Symposium on Lattice Field Theory (LATTICE2021
• 作者: Monahan, Chris;Hasenfratz, Anna;Rizik, Matthew David;Shindler, Andrea;Witzel, Oliver
• 通讯作者: Witzel, Oliver

Nonperturbative renormalization of the quark chromoelectric dipole moment with the gradient flow: Power divergences

夸克色电偶极矩与梯度流的非微扰重整化：功率散度

• DOI: 10.1103/physrevd.104.074516
• 发表时间: 2021
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Kim, Jangho;Luu, Thomas;Rizik, Matthew D.;Shindler, Andrea
• 通讯作者: Shindler, Andrea