Using Muons and Protons to Probe the Structure of the Universe

该奖项支持的主要物理项目是精确测量介子磁矩。介子是一种基本粒子，其特征与电子非常相似，但质量是电子的200倍。最终目标是将实验测量结果与所谓的粒子物理学标准模型的理论预测结果进行比较。目前的标准模型无法解释许多观测到的现象，比如暗物质的性质，或者我们宇宙中物质-反物质不对称的起源。如果被发现，实验测量和标准模型预测之间的显著差异可能会为超越标准模型（BSM）物理学的本质提供人们期待已久的见解。此外，该奖项将支持对夸克和胶子如何分裂成构成我们宇宙的物质的研究。现在一个公认的事实是，质子是由更基本的粒子组成的，这些粒子被称为夸克和胶子，它们在质子内部紧密结合。一旦被释放，夸克和胶子就会分裂，产生大量的物质和反物质粒子。该奖项支持的测量将揭示这些阵雨中产生的颗粒的数量和特征。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在国家实验室体验科学文化和参与实验。μ子测量将由费米国家加速器实验室的新g-2合作进行，该实验室建议测量μ子异常磁矩到十亿分之140。在观测水平上与标准模型预测的偏差可以用几种BSM情景来解释，而精度的提高将显著限制超对称模型的关键参数，超对称是讨论最广泛的BSM模型之一。质子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）上进行。这些实验所需的根(s) = 200GeV质子碰撞只能在RHIC上实现。射流重建技术将用于测量完全重建的射流中已识别的介子、介子和质子的产量。这些产率将提供胶子和夸克横向动量依赖的碎片函数的关键输入。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The primary physics program supported by this award is the precise measurement of the muon magnetic moment. The muon is a fundamental particle with characteristics very similar to the electron, but with 200 times the mass. The ultimate goal is to compare the experimental measurement with theoretical predictions from the so-called Standard Model of Particle Physics. The current Standard Model cannot explain many observed phenomena, such as the nature of dark matter or the origins of the matter-antimatter asymmetry in our universe. If discovered, a significant discrepancy between the experimental measurement and Standard Model predictions could provide long awaited insights into the nature of Beyond the Standard Model (BSM) physics. In addition, this award will support investigations into how quarks and gluons fragment into the matter that makes up our universe. It is now a well-established fact that protons are made up of more elementary particles, called quarks and gluons, that are bound tightly inside the proton. When liberated, the quarks and gluons break up and produce a shower of matter and antimatter particles. Measurements supported by this award will shed light on the number and characteristics of the particles produced in these showers. 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 muon measurements will be performed by the new g-2 collaboration at the Fermi National Accelerator Laboratory, which proposes to measure the muon anomalous magnetic moment to 140 parts per billion. A deviation from the Standard Model prediction at the observed level could be explained by several BSM scenarios and the improved precision will significantly constrain key parameters in supersymmetry, one of the most widely discussed BSM models. The studies of proton structure measurements will be carried out at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The root(s) = 200GeV proton collisions necessary for these experiments are only available at RHIC. Jet reconstruction techniques will be used to measure yields of identified pions, kaons and protons inside of fully reconstructed jets. These yields will provide critical input on gluon and quark transverse momentum dependent fragmentation functions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.