Nucleon Structure and Nuclear Force Studies

这个奖项是为了支持肯特州立大学的一组研究人员在实验中能核物理学方面的工作。这项研究的目标包括确定质子的固有角动量或自旋的起源，测量中子内部的电荷分布，以及研究原子核内部核力的短程相关性。研究质子自旋起源的工作将在布鲁克海文国家实验室的相对论重离子对撞机（RHIC）上作为STAR探测器合作的一部分进行。中子内部电荷分布的测量和核短程相关的研究将在杰斐逊国家加速器设施（JLab）进行。即将进行的研究建立在这个小组的力量和经验的基础上，使用大体积中子探测器和测量核反应中发射的粒子的不对称性。利用RHIC的STAR探测器测量高能质子-质子碰撞中发射粒子的不对称性，将使人们能够确定胶子对质子自旋的贡献。胶子是一种交换粒子，负责构成质子的夸克之间的力。胶子对质子自旋的贡献只能通过极化（自旋对齐）质子的碰撞来确定。这个小组为STAR探测器提供了一种新的端盖量热计，可以更好地测量粒子的不对称性。在JLab对中子电荷分布和核短程相关的测量涉及使用该小组多年来开发的大体积快中子探测器阵列。所有这些测量都将增加对核子结构和核力性质的理解。这项工作还将为现代工业、医学领域和学术界所需的博士级物理学家提供急需的培训。

This award is for support for a group of researchers at Kent State University to perform work in experimental medium-energy nuclear physics. The goals of this research include determining the origin of the intrinsic angular momentum, or spin, of the proton, measuring the charge distribution inside the neutron, and studying short-range correlations in the nuclear force inside nuclei. The work to study the origin of the spin of the proton will be performed as part of the STAR detector collaboration at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The measurements of the charge distribution inside the neutron and the study of nuclear short-range correlations will be performed at the Jefferson National Accelerator Facility (JLab). The research to be performed builds on the strength and experience of this group using large-volume neutron detectors and measuring asymmetries of particles emitted in nuclear reactions. The measured asymmetries of emitted particles in high-energy proton-proton collisions with the STAR detector at RHIC will allow one to determine the contributions of gluons to the spin of the proton. Gluons are the exchange particle responsible for the force between the quarks that make up the proton. The gluon contribution to the spin of the proton can be determined only from collisions of polarized (spin aligned) protons. This group has contributed elements to a new end-cap calorimeter for the STAR detector that will allow better measurements of the particle asymmetries. The measurements of the charge distribution of the neutron and of nuclear short-range correlations at JLab involve the use of large-volume, fast neutron detector arrays developed by this group over a number of years. All of these measurements will provide an increased understanding of the structure of the nucleon and the nature of the nuclear force. This work will provide also critically needed training of doctoral-level physicists needed in modern industry, medical fields, and academia.