3D Structure of Hadrons from Electromagnetic Probes Beyond the Leading Order of QED

来自电磁探针的强子 3D 结构超出 QED 的主序

• 批准号: 2111063
• 负责人: Andrei Afanasev
• 金额: $ 27万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2111063&HistoricalAwards=false
• 关键词: 3D; Structure; Hadrons; Electromagnetic; Probes

Key questions being addressed in modern nuclear science include, among others, (i) the role of the quarks and gluons in forming nucleons (protons and neutrons) and nuclei and (ii) fundamental symmetries governing interactions between leptons (electrons and muons) and nucleons and nuclei. The US has made significant investments into fundamental science and provided facilities for nuclear research that are aimed toward finding answers to these questions. These facilities include CEBAF at the Thomas Jefferson National Accelerator Facility, which will investigate the structure of hadrons, the set of heavy elementary particles that includes the proton and neutron, and a future Electron-Ion Collider planned at Brookhaven National Laboratory. The electrons used to probe the nuclear structure are charged particles, and while scattering off nuclear targets they inevitably emit photons or exchange extra virtual photons, presenting a challenge in interpretation in terms of hadronic structure and dynamics. This project aims to develop a unified approach that will consider both high-order electromagnetic effects and the nucleon’s structure in a theoretical description of electron scattering processes. In addition, the PI will mentor students engaged in this research, provide public lectures, and organize meeting with students in local high schools in Washington, DC.This project will advance current understanding of electromagnetic interactions of hadrons beyond the leading order in QED by developing appropriate theoretical and modelling approaches. Novel effects will be considered for elastic electron-nucleon scattering, deep-virtual electroproduction of pions, semi-inclusive deep-inelastic scattering of leptons, along with new topological states of relativistic electrons. The results of the investigation will be discussed in relation to the physics programs at Jefferson Lab and future Electron-Ion Collider at Brookhaven National Lab that aim to map 3D-structure of hadrons from precision electron scattering. Results of the project will be disseminated through a user-friendly interface mirrored at Jefferson Lab (Radiative Corrections Helpdesk) to assist nuclear physics community in developing proper physics analysis tools. Novel solutions for polarization-dependent cross sections of lepton scattering will be implemented in GEANT4 toolkit through PI’s active membership in GEANT4 Collaboration.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.

现代核科学正在解决的关键问题包括：(1)夸克和胶子在形成核子（质子和中子）和原子核中的作用；(2)控制轻子（电子和介子）、核子和原子核之间相互作用的基本对称性。美国在基础科学方面进行了大量投资，并为核研究提供了旨在寻找这些问题答案的设施。这些设施包括托马斯·杰斐逊国家加速器设施的CEBAF，它将研究强子的结构，包括质子和中子在内的一组重基本粒子，以及布鲁克海文国家实验室计划的未来电子-离子对撞机。用于探测核结构的电子是带电粒子，当它们从核目标散射出去时，不可避免地会发射光子或交换额外的虚光子，这在强子结构和动力学方面的解释上提出了挑战。该项目旨在开发一种统一的方法，将考虑高阶电磁效应和核子结构在电子散射过程的理论描述。此外，PI将指导参与这项研究的学生，提供公开讲座，并组织与华盛顿特区当地高中学生的会议。该项目将通过发展适当的理论和建模方法，推进目前对强子电磁相互作用的理解，超越QED的领先顺序。将考虑弹性电子-核子散射、介子的深虚电产生、轻子的半包容深非弹性散射以及相对论电子的新拓扑态的新效应。研究结果将与杰斐逊实验室的物理项目和布鲁克海文国家实验室未来的电子-离子对撞机进行讨论，该项目旨在通过精确的电子散射来绘制强子的3d结构。该项目的结果将通过杰弗逊实验室（辐射修正帮助台）的用户友好界面传播，以协助核物理学界开发适当的物理分析工具。通过PI在GEANT4协作中的积极成员资格，将在GEANT4工具包中实现轻子散射偏振相关横截面的新解决方案。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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

Two-Photon Exchange Effects in Semi-Inclusive Deep-Inelastic Scattering on a Nucleon

核子半包容深非弹性散射中的双光子交换效应

• 发表时间: 2021
• 期刊: APS
• 作者: A. Afanasev, Stinson Lee

Vorticity of Twisted Spinor Fields

扭曲旋量场的涡度

• 发表时间: 2022
• 期刊: ArXivorg
• 作者: A. Afanasev, C.E. Carlson

Charge-asymmetric correlations in elastic lepton- and antilepton-proton scattering from real photon emission

真实光子发射的弹性轻子和反轻子-质子散射中的电荷不对称相关性

• DOI: 10.1140/epja/s10050-022-00805-8
• 发表时间: 2022
• 期刊: The European Physical Journal A
• 作者: Afanasev, A.;Ilyichev, A.
• 通讯作者: Ilyichev, A.