Structure of the Nucleon and Few-Body Nuclear Systems with Electron Scattering

具有电子散射的核子和少体核系统的结构

• 批准号: 1714809
• 负责人: Gerassimos Petratos
• 金额: $ 52.4万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1714809&HistoricalAwards=false
• 关键词: Structure; Nucleon; Few; Body; Nuclear

This award is to support a suite of nuclear physics experiments at the Jefferson National Laboratory (JLab). Electrons from the JLab accelerator will be scattered from light mass nuclear targets, the scattered electrons will then be detected in instruments located in the experimental halls. By measuring the number of scattered electrons at different positions in the detectors, the PIs will be able to compare the experimental results to theoretical models that predict the internal structure of the proton and neutron. Knowing this structure plays a critical role in understanding the strong force, one of the four principal forces that determine the structure of the universe as we know it. The supported investigators will play a major, leading role in all aspects of the project, namely the preparation of all experimental apparatuses to be used, the acquisition of the experimental data, the data analysis, and the publication of the results. The graduate students involved will be exposed to and gain expertise with both hardware and software development. The project is expected to make significant contributions to the advancement of basic nuclear physics science, and to graduate education and training. The project will result in doctoral dissertation topics on related science and instrumentation, which provide the experience needed for careers in education, medical physics, homeland security, technology, and research at national laboratories.The supported research will provide fundamental information on the momentum distributions of the quarks inside the proton and neutron, by using a novel method of directly comparing measurements of inelastic electron scattering from helium-3 (3He) and tritium (3H) nuclei. This method is complementary to that used in past experiments at the Stanford Linear Accelerator Center, which showed the existence of point-like "partons" inside the nucleons, by utilizing inelastic electron scattering from hydrogen and deuterium (2H) nuclei. The new method will eliminate inherent theoretical uncertainties present in the Stanford method. The results will test long-standing predictions of the Quark Model of the nucleon, and of Quantum Chromodynamics, the theory describing the interactions between quarks and gluons. A secondary goal of the award is the improvement and re-submission of a proposal to be submitted to the JLab Proposal Advisory Committee for a measurement of the elastic charge and magnetic form factors of the 3H nucleus, which will provide critical information for the development of a "standard model" describing the structure and dynamics of the simplest, lightest nuclei in nature.

该奖项旨在支持杰斐逊国家实验室（JLab）的一系列核物理实验。来自JLab加速器的电子将从轻质量核目标散射，然后在实验霍尔斯的仪器中检测散射的电子。通过测量探测器中不同位置的散射电子数量，PI将能够将实验结果与预测质子和中子内部结构的理论模型进行比较。了解这种结构对于理解强作用力（我们所知道的决定宇宙结构的四种主要力之一）起着至关重要的作用。受支持的研究人员将在项目的各个方面发挥重要的主导作用，即准备所有实验设备，获取实验数据，数据分析和结果发表。 参与的研究生将接触并获得硬件和软件开发的专业知识。预计该项目将对基础核物理科学的进步以及研究生教育和培训做出重大贡献。该项目将产生相关科学和仪器的博士论文主题，为教育，医学物理，国土安全，技术和国家实验室研究的职业生涯提供所需的经验。支持的研究将提供质子和中子内夸克动量分布的基本信息，采用直接比较测量氦-3（3 He）和氚（3 H）核非弹性电子散射的新方法。 这种方法是对斯坦福大学直线加速器中心过去实验的补充，该实验通过利用氢和氘（2 H）核的非弹性电子散射显示了核子内部点状“部分子”的存在。 新方法将消除斯坦福大学方法中固有的理论不确定性。 这些结果将检验核子夸克模型和量子色动力学（描述夸克和胶子之间相互作用的理论）的长期预测。 该奖项的第二个目标是改进和重新提交一份提交给JLab提案咨询委员会的提案，以测量3 H核的弹性电荷和磁性形状因子，这将为开发描述自然界中最简单，最轻的核的结构和动力学的“标准模型”提供关键信息。