RUI: Fundamental Symmetry Experiments with Muons

在核物理学领域的基本对称性的研究探讨了定义宇宙的物质，能量和力量的性质，并允许恒星，行星和生命的出现和繁荣。 该奖项将支持PI和本科生进行两项实验，以进一步了解宇宙。 第一个实验名为MuSun，解决了与质子-质子融合过程相关的计算中最重要的限制之一，该过程释放了太阳等恒星的大部分能量。 它将提供数据，校准这些计算中最不精确的部分，也可以应用于其他重要的核反应。 第二个被称为Muon g-2实验，测试我们的粒子标准模型及其相互作用。 虽然这种模式非常成功，但它并不完整。 该实验的上一代发现了其测量值与标准模型预测之间存在差异的强烈暗示;新实验将以足够的精度对其进行探测，以可能声称发现。学生将有机会进行与更大的物理目标相关的指导研究，在主要研究机构工作，并参加会议和合作会议。 这项资助将提供机会，让有才华和多元化的理科学生参与进来，并为他们提供支持，其中包括女性、代表性不足的族裔成员和第一代大学生。MuSun测量氘中μ子的捕获率，这是一个基本的双核子过程，为轻核弱相互作用的有效场论提供了校准。 MuSun实验研究的μ子捕获过程类似于包括质子-质子聚变和用于在萨德伯里中微子天文台检测中微子的氘分裂反应。 MuSun的结果将大大提高描述这些反应的手征有效场论中描述双核子项的低能常数的精度。费米实验室的Muon g-2实验将是该小组在此资助期内的主要重点。这个实验通过观察μ子束在精确匀场的储存环磁体中循环时的自旋进动速率来测量μ子的反常磁矩。自旋极化旋进是因为与虚粒子的耦合，包括标准模型描述的所有粒子，以及可能的任何新的、尚未发现的粒子和超越它的相互作用。瑞吉斯小组将负责实施、安装、调试和分析光纤竖琴光束监测器和入口计数器。 这种测量显然有可能发现标准模型之外的新物理。 布鲁克海文国家实验室的实验精度为百万分之0.5，与现代标准模型的计算结果相比，误差超过三个标准差;偶然出现这种水平波动的概率小于千分之一。 当实验的精度达到百万分之0.14的目标时，差异可能会超过5个标准差的发现阈值。 这样的发现可能代表了超对称性、新规范玻色子（例如暗光子）或其他新粒子或相互作用的发现。

The study of fundamental symmetries in the field of nuclear physics explores the nature of the matter, energy, and forces that define the universe and that have allowed stars, planets, and life to emerge and flourish. This award will support the PI and undergraduate students to work on two experiments that will further our understanding of that universe. The first experiment, called MuSun, addresses one of the most important limitations of calculations related to the proton-proton fusion process that releases most of the energy in stars like the Sun. It will provide data that will calibrate the least precise parts of these calculations and can also be applied to other important nuclear reactions. The second, known as the Muon g-2 experiment, tests our Standard Model of particles and their interactions. While this model has been remarkably successful, it is not complete. The previous generation of this experiment uncovered a strong hint of a discrepancy between its measurement and the Standard Model's prediction; the new experiment will probe it with enough precision to potentially claim a discovery.Students will have opportunities to carry out guided research related to the larger physics goals, to work at major research facilities, and to attend conferences and collaboration meetings. This grant will provide opportunities to involve and support a talented and diverse group of science students that includes women, members of underrepresented ethnic groups, and first-generation college students.MuSun measures the rate of muon capture in deuterium, a fundamental two-nucleon process that provides a calibration of effective field theories of weak interactions in light nuclei. The muon capture process studied by the MuSun experiment is analogous to reactions that include proton-proton fusion and the deuteron breakup reactions that were used to detect neutrinos at the Sudbury Neutrino Observatory. The MuSun result will dramatically improve the precision of the low-energy constants describing two-nucleon terms in chiral effective field theories that describe these reactions. The Muon g-2 experiment at Fermilab will be the group's primary focus for this grant period. This experiment measures the anomalous magnetic moment of the muon by observing the rate of spin precession of a muon beam as it circulates in a precisely shimmed storage ring magnet. The spin polarization precesses because of coupling to virtual particles, including all of the particles described by the Standard Model and potentially any new, as-yet-undiscovered particles and interactions that are beyond it. The Regis group will be responsible for the implementation, installation, commissioning, and analysis for the fiber harp beam monitors and entrance counters for this experiment. The measurement clearly has the potential to discover new physics beyond the Standard Model. When the existing precision of 0.5 parts per million from the Brookhaven National Laboratory experiment is compared with modern Standard Model calculations, there is a discrepancy of more than three standard deviations; the probability of a fluctuation at this level by chance is less than one in a thousand. As the precision of the experiment reaches its 0.14 part-per-million goal, the discrepancy could exceed the discovery threshold of five standard deviations. Such a finding could represent the discovery of supersymmetry, new gauge bosons such as dark photons, or other new particles or interactions.