RUI: Hadron Structure and Interactions

质子是一种粒子，它是我们理解宇宙中物质的核心。它存在于每个原子的原子核中，并为恒星提供燃料的聚变反应做出贡献。质子是由称为夸克、反夸克(夸克的反物质对应物)和胶子的基本物质组成的，但这些成分对质子性质的贡献还不完全清楚。例如，质子有一种名为自旋的属性，它被用于核磁共振扫描等医学应用，但夸克和胶子的自旋如何结合起来产生质子的自旋的详细知识仍然缺乏。在这个项目中，研究人员将使用理论模型来研究奇怪夸克和反夸克对质子性质的贡献，并将结果与费米国家加速器实验室和杰斐逊国家加速器设施等设施的实验测量进行比较。本科生将参与该项目，接受核物理和粒子物理方面的培训，这是对他们本科课程的补充，并在研究方法和科学交流方面获得经验。学生们将在专业会议上展示他们的作品，并向更广泛的公众展示他们的作品。该项目的目标是确定质子的奇异性分布以及奇异性对质子电磁性质的贡献。质子中的奇怪是指它的奇怪和反奇怪的夸克，这些夸克是由质子涨落到介子-重子态或由夸克和胶子相互作用产生的。奇异性分布描述了由奇异性夸克或反奇异性夸克携带的质子动量份额，它们可能彼此不同(奇异性不对称)。奇异性分布对于我们理解质子的结构很重要，也因为它们会影响暗物质搜索的预测截面。PI和她的学生将开发一个介子云模型，将质子的波动表示为一对奇怪的介子和奇怪的重子。统计模型将被用来描述夸克和胶子相互作用在介子和重子中产生的奇怪分布。将与完全陌生和陌生不对称的实验结果进行比较。奇异性波函数的光锥模型将被用来计算奇异性电磁形状因子，由此可以从实验测量中确定核子中奇异性的极限。

The proton is a particle that is central to our understanding of matter in the universe. It is found in the nucleus of every atom and contributes to the fusion reactions that fuel the stars. Protons are constructed from basic building blocks of matter called quarks, antiquarks (the antimatter counterparts of the quarks) and gluons, but the ways in which these constituents contribute to the properties of the proton are not completely understood. For example, the proton has a property called spin, which is used in medical applications such as MRI scans, but detailed knowledge of how the spins of the quarks and gluons combine to give the spin of the proton is still missing. In this project the investigator will use theoretical models to study the contributions of strange quarks and antiquarks to the properties of the proton and compare the results to experimental measurements from facilities such as the Fermi National Accelerator Laboratory and the Jefferson National Accelerator Facility. Undergraduate students will participate in the project, receive training in nuclear and particle physics that is complementary to their undergraduate coursework and gain experience in research methods and scientific communication. The students will present their work at professional meetings and to the broader public. The goal of this project is to determine the strangeness distributions of the proton and the contribution of strangeness to the proton's electromagnetic properties. Strangeness in the proton refers to its strange and anti-strange quarks, which are created by fluctuations of the proton into meson-baryon states or by quark and gluon interactions. Strangeness distributions describe the share of the proton's momentum that is carried by the strange or anti-strange quarks, which may differ from one another (strangeness asymmetry). Strangeness distributions are important both for our understanding of the structure of the proton, and because they affect the cross sections predicted for dark matter searches. The PI and her students will develop a meson cloud model to represent the fluctuations of the proton into pairs of strange mesons and strange baryons. A statistical model will be used to describe the strange distributions that are created in the mesons and baryons by quark and gluon interactions. Comparison will be made with experimental results for total strangeness and strangeness asymmetry. A light cone model of strangeness wave functions will be used to calculate strangeness electric and magnetic form factors, from which limits on strangeness in the nucleon can be determined from experimental measurements.