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

对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的内部结构，并了解束缚这些最基本的核物理元素的动力学，是推进这一知识的关键部分。该项目旨在进行前沿研究，以构建对确认对质子结构的理解至关重要的中性粒子谱仪(NPS)。NPS在杰斐逊国家加速器设施实现了一个多方面的实验物理计划，在这个计划中，PI发挥着主导作用。博士后研究人员、研究生和本科生的参与是该项目不可或缺的一部分，并有助于美国技术工作队伍的发展。全由女性组成的项目领导人将提供榜样，鼓励代表不足的小组在物理或技术领域继续深造。核动力源提供的中性粒子探测和高分辨率磁谱仪的双臂组合提供了独特的科学能力，通过与要求精度和高光度的中性粒子发生反应，推动研究核子横向空间和动量结构的能量尺度。NPS可以精确测量所谓的硬排斥(反冲质子在高能电子-夸克散射过程中保持不变)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丰富的质子结构信息，在精确的测量中显示出对散射过程的了解是至关重要的，这推动了能量尺度。使用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。该仪器将由天主教大学领导的一个财团的研究人员合作建造。美国大学和俄亥俄大学。它还将包括老自治领大学。作为非牵头合作伙伴，杰斐逊实验室、北卡罗来纳农工大学、埃里温物理研究所、格拉斯哥大学和奥赛核物理研究所。

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.