MRIConsortium: Development of a Neutral Particle Spectrometer to Investigate the Quark Structure of the Proton at JLab 12 GeV

获得强束缚系统性质的定量描述对于我们理解物质的基本结构和起源是非常重要的。揭示包含质子和中子的原子核心的内部结构，并理解将这些最基本的核物理元素结合在一起的动力学是推进这一知识的重要组成部分。该项目旨在开展前沿研究，构建中性粒子光谱仪（NPS），这对确认质子结构的理解至关重要。NPS使杰斐逊国家加速器设施能够开展多方面的实验物理计划，其中pi发挥主导作用。博士后研究人员、研究生和本科生的参与是该项目不可分割的一部分，并有助于美国技术劳动力的发展。全女性项目领导将提供榜样，鼓励代表性不足的群体在物理或技术领域进行高级研究。NPS提供的双臂中性粒子探测与高分辨率磁谱仪相结合，提供了独特的科学能力，可以推动能量尺度，通过与需要精度和高亮度的中性粒子的反应来研究核子的横向空间和动量结构。NPS允许精确测量所谓的硬独占（反冲质子在高能电子-夸克散射过程中保持完整）和半包容（电子-夸克散射过程的能量损失主要被单个介子或介子吸收）散射过程。为了通过空间和动量成像提取关于质子结构的丰富信息，在推动能量尺度的精确测量中显示散射过程的理解是至关重要的。用NPS对真实光子或中性介子的精确测量在这里提供了独特的优势。该仪器将由由美国天主教大学和俄亥俄大学领导的研究人员组成的一个联盟合作建造，它还将包括老道明大学和杰斐逊实验室、北卡罗来纳州农工大学、埃里温物理研究所、格拉斯哥大学和奥赛核物理研究所等非主要合作伙伴。

Gaining a quantitative description of the nature of strongly bound systems is of great importance for our understanding of the fundamental structure and origin of matter. Revealing the inner structure of the core of the atom that contains the protons and neutrons and understanding the dynamics that bind these most basic elements of nuclear physics is an essential part to advance this knowledge. This project is aimed at conducting leading-edge research to construct a neutral particle spectrometer (NPS) critical to confirm the understanding of the structure of the proton. The NPS enables a multifaceted experimental physics program at the Jefferson National Accelerator Facility, in which the PIs play a leading role. The participation of postdoctoral researchers, graduate students, and undergraduate students is an integral part of this project and contributes to the development of the technological work force in the USA. The all-female project leadership will provide role models that could encourage under-represented groups to pursue advanced studies in physics or technical fields.The two-arm combination of neutral-particle detection as provided by the NPS and a high-resolution magnetic spectrometer offers unique scientific capabilities to push the energy scale for studies of the transverse spatial and momentum structure of the nucleon through reactions with neutral particles requiring precision and high luminosity. The NPS allows accurate access to measurements of so-called hard exclusive (the recoiling proton stays intact in the energetic electron-quark scattering process) and semi-inclusive (the energy loss of the electron-quark scattering process gets predominantly absorbed by a single pion or kaon) scattering processes. To extract the rich information on proton structure through spatial and momentum imaging, it is of prime importance to show in accurate measurements, pushing the energy scales, that the scattering process is understood. Precision measurements of real photons or neutral-pions with the NPS offer unique advantages here. The instrument will be built by a collaboration of researchers forming a consortium led by the Catholic Univ. of America and Ohio Univ. It will also include the Old Dominion Univ. and as non-lead partners, the Jefferson Lab, North Carolina A&T University, the Yerevan Physics Institute, U. of Glasgow, and the Institute of Nuclear Physics at Orsay.