RUI: Hadronic Structure and Interactions

这项研究集中在两个领域：（i）强子性质的描述，其组成夸克和胶子，和（ii）的反质子-质子相互作用的奇异性和魅力的生产。 (i)一个混合的方法将被用来描述强子性质的微扰和非微扰过程。 统计模型将代表微扰自由度，介子云模型将代表重子到介子-重子态的非微扰涨落。 对π-核子形状因子的研究将减少π云对这个和其他强子结构计算的贡献的模型依赖性。 该项目将解决最近的实验对理论提出的突出挑战之一，质子海中轻夸克分布的动量依赖性，并确定部分子对质子奇异性和自旋的贡献。 预测将在费米实验室运行的实验和计划在JPARC。 (ii)在反质子-质子湮灭中产生的反超子-超子对测试了描述奇异性和粲产生的理论模型。 这些反应的夸克模型计算和反应矩阵分析将进行比较介子交换和组分夸克模型，并从欧洲核子研究中心，不同意所有的理论计算最近的自旋转移测量结果。 将为FAIR的PANDA合作计划的实验计算横截面和自旋可观测量，这将把CERN的测量扩展到更高的能量和粲超子的产生。 核子（质子和中子）和其他强子是由夸克、胶子和波动的夸克-反夸克对组成的粒子。 在这项研究中，我们研究的基本问题是粒子的性质是如何由其成分的性质，以及这些成分如何影响粒子相互作用的方式。 这类问题的一个例子是质子自旋。 质子的自旋是1/2，但它由许多夸克（自旋1/2）和胶子（自旋1）组成。 所有这些自旋加起来是如何给我们一个自旋为1/2的质子的？ 这项工作将与来自西雅图大学的本科生研究助理一起进行。 他们的研究经验将提供课堂学习和当代研究的兴奋的整合。 学生将接受研究方法和科学交流方面的培训。 他们将在团队中工作，指导年轻的学生，并在专业协会的会议上发表论文，海报和演讲。 他们还将在由西雅图大学学生研究组织赞助的研讨会和活动中与当地校园社区分享他们的工作。

This research focuses on two areas: (i) the description of hadron properties in terms of their constituent quarks and gluons, and (ii) the production of strangeness and charm in antiproton-proton interactions. (i) A hybrid approach will be used to describe hadron properties in terms of both perturbative and non-perturbative processes. A statistical model will represent perturbative degrees of freedom, and a meson cloud model will represent the nonperturbative fluctuation of baryons into meson-baryon states. A study of the pion-nucleon form factor will reduce the model-dependence of pion cloud contributions to this and other hadron structure calculations. This project will address one of the outstanding challenges to theory posed by recent experiment, the momentum-dependence of light quark distributions in the proton sea, and determine the parton contributions to strangeness and spin in the proton. Predictions will be made for experiments running at Fermilab and planned at JPARC. (ii) The creation of antihyperon-hyperon pairs in antiproton-proton annihilations tests theoretical models for the description of strangeness and charm production. Quark model calculations and reaction matrix analyses of these reactions will be made and compared to meson-exchange and constituent quark models, and to recent spin transfer measurement results from CERN, which disagree with all theoretical calculations. Cross sections and spin observables will be calculated for the experiments planned by the PANDA collaboration at FAIR, which will extend the CERN measurements to higher energies and to the production of charmed hyperons. Nucleons (protons and neutrons) and other hadrons are particles composed of quarks, gluons, and a fluctuating sea of quark-antiquark pairs. In this research we study the fundamental questions of how the properties of a particle are determined by the properties of its constituents, and how those constituents affect the ways in which particles interact with one another. An example of this type of question is proton spin. The proton spin is 1/2, but it consists of many quarks (spin 1/2) and gluons (spin 1). How do all these spins add up to give us a spin-1/2 proton? This work will be carried out with undergraduate research assistants from Seattle University. Their research experience will provide an integration of classroom learning and the excitement of contemporary research. Students will receive training in research methods and scientific communication. They will work in teams, mentor younger students and present their work in papers, posters and talks at meetings of professional societies. They will also share their work with the local campus community in seminars and events sponsored by Seattle University student research organizations.