Abstract

Helium is a prototype three-body system and has long been a model system for developing quantum mechanics theory and computational methods. The fine-structure splitting in the 2³P state of helium is considered to be the most suitable for determining the fine-structure constant α in atoms. After more than 50 years of efforts by many theorists and experimentalists, we are now working toward a determination of α with an accuracy of a few parts per billion, which can be compared to the results obtained by entirely different methods to verify the self-consistency of quantum electrodynamics. Moreover, the precision spectroscopy of helium allows determination of the nuclear charge radius, and it is expected to help resolve the ‘proton radius puzzle’. In this review, we introduce the latest developments in the precision spectroscopy of the helium atom, especially the discrepancies among theoretical and experimental results, and give an outlook on future progress.

中文翻译：

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原子氦的精密光谱

 抽象的

氦是一个原型三体系统，长期以来一直是发展量子力学理论和计算方法的模型系统。氦的 2 ³ P态的精细结构分裂被认为最适合确定原子中的精细结构常数α。经过许多理论家和实验家50多年的努力，我们现在正在努力以十亿分之几的精度确定α，可以与完全不同方法获得的结果进行比较，以验证其自洽性量子电动力学。此外，氦的精密光谱可以确定核电荷半径，有望帮助解决“质子半径之谜”。在这篇综述中，我们介绍了氦原子精密光谱学的最新进展，特别是理论与实验结果之间的差异，并对未来的进展进行了展望。