Spin as a Probe into the Structure of the Universe

现在一个公认的事实是，核子、质子和中子是由更基本的称为夸克的粒子组成的。这项拨款支持的主要物理计划是测量夸克的磁矩如何对质子的总磁矩做出贡献，以及质子内部其他亚原子粒子的贡献。此外，这笔赠款将支持费米国家加速器实验室一项名为E989的实验的研究，该实验将精确测量基本粒子--Muon--的磁矩，它类似于电子，但质量更大。这些实验的目的是将实验结果与所谓的粒子物理标准模型的理论预测进行比较。这里描述的研究将为研究生提供必要的工具和知识，以便在其他大型对撞机或较小的非加速器合作中获得博士后工作。获得该奖项资助的本科生将继续有难得的机会体验科学文化并参与国家实验室的实验。质子自旋结构测量的研究将在布鲁克海文国家实验室的相对论重离子对撞机(RHIC)进行。这些实验所需的纵向和横向极化质子束只有在RHIC才能获得。喷流重建技术将用于测量对胶子螺旋度和夸克横度分布敏感的不对称性。该奖项还将支持费米国家加速器实验室新的G-2实验(E989)，该实验提议将Muon反常磁矩测量到百万分之0.14。在观测水平上与标准模型预测的偏差可以用几种超出标准模型(BSM)的情景来解释，而且提高的精度将显著限制超对称中的关键参数，超对称是讨论最广泛的BSM模型之一。

It is now a well-established fact that nucleons, protons and neutrons, are made up of more elementary particles called quarks. The main physics program supported by this grant is to measure how the magnetic moments of quarks contribute to the total magnetic moment of the proton, along with contributions from other subatomic particles inside the proton. In addition, this grant will support research on an experiment at Fermi National Accelerator Laboratory, labeled E989, which will precisely measure the magnetic moment of a fundamental particle, the muon, which is like an electron but with more mass. The goal of these experiments is to compare experimental result with theoretical predictions from the so-called Standard Model of Particle Physics. The studies described here will provide graduate students with the necessary tools and knowledge to obtain post-doctoral work at other large colliders or smaller non-accelerator based collaborations. Undergraduate students funded by this award will continue to have the rare opportunity to experience the scientific culture and participate in experiments at National Laboratories.The studies of proton spin structure measurements will be carried out at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Longitudinally and transversely polarized proton beams necessary for these experiments are only available at RHIC. Jet reconstruction techniques will be used to measure asymmetries sensitive to the gluon helicity and quark transversity distributions. This award will also support the new g-2 experiment (E989) at the Fermi National Accelerator Laboratory, which proposes to measure the muon anomalous magnetic moment to 0.14 parts per million. A deviation from the Standard Model prediction at the observed level could be explained by several Beyond the Standard Model (BSM) scenarios and the improved precision will significantly constrain key parameters in supersymmetry, one of the most widely discussed BSM models.