Spectroscopy of the fundamental few-lepton systems Ps and Ps-

基本少轻子系统 Ps 和 Ps- 的光谱学

• 批准号: 59983031
• 负责人: Professor Dr. Dietrich Habs
• 金额: --
• 依托单位: Lehrstuhl für Experimentalphysik - Medizinische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/59983031?language=en
• 关键词: Spectroscopy; fundamental; few; lepton; systems

Precision experiments will be performed on the properties of the purely leptonic fewbody systems Ps- (e+e-e-) and Ps (e+e-), exploiting the unprecedented intensity of the positron source at the FRM II in Garching. The decay rate of Ps- will be measured to an accuracy of about 0.1%, thus allowing for sensitive tests of QED predictions in this fundamental 3-body system. For the first time the photodetachment cross section of Ps- will be measured as well as autoionizing doubly-excited Ps- resonance states, allowing for the first determination of the binding energy of Ps- and a comparison with precise theoretical predictions. Photo-ionization of Ps- will allow to produce a pure, energy-variable 3S1 Ps beam. Using a different Ps production method and the same laser system as for the Ps- excitation, fundamental precision studies on the 1S-2S transition frequency in 3S1 Ps are envisaged, aiming at an improvement of the present best experimental value by an order of magnitude based on the unprecedented intensity of the positron source and the ultra-precise frequency measurement using the frequency comb technology.

利用Garching FRM II中前所未有的正电子源强度，将对纯轻子少体系统Ps- (e+e-e-)和Ps （e+e-）的性质进行精密实验。Ps-衰变率的测量精度将达到约0.1%，从而允许在这个基本的三体系统中对QED预测进行灵敏的测试。Ps-的光分离截面将首次被测量，以及自电离双激发的Ps-共振态，从而首次确定Ps-的结合能，并与精确的理论预测进行比较。Ps-的光电离将允许产生纯粹的，能量可变的3S1 Ps光束。设想使用与Ps-激发不同的Ps产生方法和相同的激光系统，对3S1 Ps中的1S-2S跃迁频率进行基本精度研究，目的是基于前所未有的正电子源强度和使用频率梳技术的超精密频率测量，将目前的最佳实验值提高一个数量级。