RUI: Study of Nucleon Structure via Electron Scattering at JLab

已经确定质子和中子(核子)有一个由称为夸克和胶子的基本组成粒子组成的子结构。量子色动力学(QCD)是关于这些成分如何相互作用从而产生强大的核力和核子的基本性质的既定理论。这项拨款支持的研究计划旨在提高对核子结构的基本理解。这一目标将通过在托马斯·杰斐逊国家加速器设施进行的电子散射实验来实现。这些实验将测量质子和中子中电荷和电流的空间分布；这些信息被编码在核子电磁形状因数中。从QCD的角度对核子形状因子有一个基本的理解，这是当今核物理学面临的突出挑战之一。夸克为什么以及如何形成只有质子和中子两种稳定构型的无色强子？解决这一挑战的一个重要步骤是通过形状因数测量来表征核子的内部结构。预期的研究活动将涵盖一系列硬件和软件项目。这些项目将为本科生提供出色的研究机会，进一步提高他们在课堂之外的教育，为他们在科学、技术、工程和数学(STEM)领域的职业生涯做好准备，并为成功的研究生学习奠定基础。对该研究项目的资金支持将使PI和克里斯托弗·纽波特大学的学生能够为杰斐逊实验室的一些项目做出贡献，这些项目旨在提高对核子结构的基本理解。拟议的项目包括一个实验工作--超级大比特光谱仪计划(SBS)--和一个现象学工作--CTEQ-JLab(CJ)--这两个项目都解决了QCD框架中强子结构的基本问题。SBS计划包括高影响实验，研究质子和中子在比先前研究的动量传递高得多的情况下的电磁形状因子。开发一种在SBS运行期间与气体电子倍增器(GEM)跟踪探测器一起使用的流式读出数据采集系统，对于长期运行JLab的高光度实验至关重要。来自SBS实验的新数据将允许执行形状因素的部分风味分解，这反过来可以使用CJ Effort提供的计算进行测试。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

It has been established that protons and neutrons (nucleons) have a substructure made up of elementary constituent particles called quarks and gluons. Quantum Chromodynamics (QCD) is an established theory of how these constituents interact giving rise to the strong nuclear force and the fundamental properties of nucleons. The research program supported by this grant is aimed at improving the fundamental understanding of nucleon structure. This goal will be achieved through electron scattering experiments to be performed at the Thomas Jefferson National Accelerator Facility. These experiments will measure the spatial distributions of electric charge and current in both the proton and the neutron; this information is encoded in the nucleon electromagnetic form factors. A fundamental understanding of the nucleon form factors in terms of QCD is one of the outstanding challenges in nuclear physics today. Why and how do quarks form colorless hadrons with only two stable configurations, the proton and neutron? One important step towards addressing this challenge is to characterize the internal structure of the nucleon via form factor measurements. The anticipated research activities will cover a range of both hardware and software projects. These projects will provide outstanding research opportunities for undergraduate students, furthering their education outside the classroom, preparing them for a career in science, technology, engineering and mathematics (STEM) and laying the foundations for successful graduate studies.The funding support for this research program will enable the PI and Christopher Newport University students to contribute to a number of projects at Jefferson Lab, aimed at improving the fundamental understanding of nucleon structure. The proposed projects include an experimental effort – the Super Bigbite Spectrometer program (SBS) – and a phenomenology effort – CTEQ-JLab (CJ) – both of which address fundamental questions of hadronic structure in the QCD framework. The SBS program comprises high impact experiments studying the electromagnetic form factors of both the proton and neutron at a much higher momentum transfer than previously studied. The development of a streaming readout data acquisition system for use with Gas Electron Multiplier (GEM) tracking detectors during the SBS running will be essential for running the high luminosity experiments at JLab in the longer term. The new data from the SBS experiments will allow a partonic flavor decomposition of the form factors to be performed, which in turn can be tested using calculations provided by the CJ effort.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.