RUI: High-Precision Atomic Structure Measurements and Tests of Fundamental Physics in Group IIIA Atoms

这一研究项目位于一所本科院校，涉及激光和原子的桌面实验，以深入了解所谓的“粒子物理标准模型”，该模型通常由大型粒子加速器的物理学家研究。在目前的工作中，金属原子Tl和In的性质被测量到了非常高的精度。然后，将结果与这些相同性质的最先进的理论计算进行比较，因为这些测量所探索的基本物理现象的高质量测试关键依赖于精确的实验结果的组合，并得到准确的、独立的原子结构计算。学生参与实验工作的方方面面，设计和测试激光、光学和信号处理系统，并执行数据收集和数据分析程序。近几十年来，使用激光的高精度原子物理实验为粒子物理标准模型的物理学贡献了重要的见解。这样的低能物理测试是对基于加速器的实验工作的补充。这些效应的小尺寸需要非常高的精度，对系统误差的广泛研究，以及仔细的实验设计。此外，高能物理在原子中的这些表现形式的大小随着原子序数Z的变化而急剧扩大，这表明使用了非常重的(因此也是复杂的)原子系统。然而，为了让这些对重原子的测量提供对标准模型的明确测试，需要对原子波函数进行同样精确的原子理论模型，以区分普通的量子力学行为和目标的“奇异”粒子物理现象。PI和他的学生继续进行一系列正在进行的半导体激光光谱分析，测量IIIA族原子(铊、铟)的原子性质，可以与最先进的原子理论计算进行比较。他们既研究加热的蒸汽室中的原子，也研究密集的准直原子束装置中的原子。这些原子包含三个价电子，挑战了精确计算波函数所需的近似技术。这种实验-理论的相互作用在最近几年显著提高了精度，因此改进了这些重原子系统中基于原子物理的基本粒子物理过程的测试。从长远来看，该小组计划进行一项新的实验，利用其违反宇称的旋光签名来测量铊原子束中的弱相互作用，改进了几年前包括PI在内的一个小组的实验结果。

This research program, located at an undergraduate institution, involves table-top experiments with lasers and atoms to gain insights into the so-called "Standard Model of particle physics" that is typically studied by physicists at large particle accelerator facilities. In the present work, properties of the metal atoms thallium and indium are measured to very high accuracy. Results are then compared to state-of-the-art theoretical calculations of these same properties, as high-quality tests of the fundamental physics phenomena probed by these measurements rely critically on the combination of precise experimental results reinforced by accurate, independent atomic structure calculations. Students become involved in all aspects of the experimental work, designing and testing laser, optical, and signal processing systems, and carrying out data collection and data analysis procedures.Over recent decades, highly-precise atomic physics experiments using lasers have contributed important insights into the physics of the Standard Model of particle physics. Such low-energy physics tests complement accelerator-based experimental work. The small size of these effects demands very high precision, extensive study of systematic errors, and careful experimental design. Also, the size of these manifestations of high-energy physics in atoms scale dramatically with Z, the atomic number, suggesting the use of very heavy (and therefore complicated) atomic systems. Yet in order for these measurements in heavy atoms to provide unambiguous tests of the Standard Model, equally precise atomic theory models of the atomic wavefunctions are required to distinguish the ordinary quantum mechanical behavior from the "exotic" particle physics phenomena being targeted. The PI and his students are continuing with an ongoing series of diode laser spectroscopy measurements of the atomic properties of Group IIIA atoms (thallium, indium) which can be compared to state-of-the-art atomic theory calculations. They study atoms both in heated vapor cells as well as a dense, collimated atomic beam apparatus. These atoms contain three valence electrons, challenging the approximation techniques required to accurately compute wavefunctions. This experiment-theory interplay has resulted in significantly improved accuracy in recent years, and therefore improved atomic-physics-based tests of fundamental particle physics processes in these heavy atomic systems. In the longer term, the group is planning to perform a new experiment to measure the Weak Interaction in an atomic beam of thallium atoms, using its parity-violating optical rotation signature, improving upon an experimental result by a group that included the PI some years ago.