RUI: Calculation of Higher Order Corrections to Positronium Energy Levels

RUI：正电子能级高阶修正的计算

基本信息

批准号：
1707489
负责人：
Gregory Adkins
金额：
$ 18万
依托单位：
Franklin and Marshall College
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707489&HistoricalAwards=false
关键词：
RUI Calculation Higher Order Corrections

项目摘要

Positronium is a bound state of an electron and its antiparticle, a positron. As such, it forms an "exotic atom," similar in many ways to the traditional simple atoms such as hydrogen and helium, but different because of its unique composition and because of its tendency to annihilate, transforming into pure electromagnetic energy in the form of high-energy photons. Many properties of positronium, such as energy levels and lifetimes, are accessible to high-precision experiments. Positronium properties can also be calculated theoretically to high precision using the methods of bound-state Quantum Electrodynamics (QED) because strong and weak interaction effects are negligible in this system. Consequently, positronium is an ideal system for testing the limits of electromagnetic bound state physics. The activities involved in calculating the positronium energy levels will be of great educational value to the undergraduate students involved as collaborators in this work. The students will learn theoretical methods and techniques of calculation more advanced than those usually encountered at the undergraduate level. They will gain valuable experience by doing the research, by presenting their results at professional meetings, and by publishing their work as co-authors in research journals.Positronium energy levels of low-lying states (n=1 and n=2) have been measured with uncertainties of roughly one MHz, and experiments are presently being developed to significantly reduce some of these uncertainties. The 2S-1S transition is of particular interest because it has the smallest natural linewidth and thus the greatest potential for improvement. The ground state hyperfine splitting is of interest because the most precise experimental results are not in accord with current theory. These transition energies and more will be calculated to a new level of precision. The calculations will be based on the low-energy effective quantum field theory NRQED (Non-Relativistic QED), which provides a natural and efficient framework for the study of non-relativistic atoms.

正电子是电子及其反粒子正电子的束缚态。因此，它形成了一种“奇异原子”，在很多方面与氢和氦等传统的简单原子相似，但由于其独特的成分以及其湮灭的倾向而有所不同，以转化为纯电磁能的形式。高能光子。正电子素的许多特性，例如能级和寿命，都可以通过高精度实验获得。正电子的性质也可以使用束缚态量子电动力学（QED）的方法从理论上进行高精度计算，因为在该系统中强相互作用和弱相互作用的影响可以忽略不计。因此，正电子素是测试电磁束缚态物理极限的理想系统。计算正电子能级的活动对于参与这项工作的本科生来说具有很大的教育价值。学生将学习比本科阶段通常遇到的更先进的理论方法和计算技术。他们将通过进行研究、在专业会议上展示他们的结果以及在研究期刊上作为合著者发表他们的研究成果来获得宝贵的经验。低洼态（n=1 和 n=2）的正电子能级已被确定。测量的不确定性约为 1 MHz，目前正在开发实验以显着降低其中一些不确定性。 2S-1S 过渡特别令人感兴趣，因为它具有最小的自然线宽，因此具有最大的改进潜力。基态超精细分裂之所以令人感兴趣，是因为最精确的实验结果与当前理论不符。这些跃迁能量及更多能量的计算精度将达到新的水平。计算将基于低能有效量子场论NRQED（非相对论QED），该理论为非相对论原子的研究提供了一个自然而有效的框架。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Calculation of higher order corrections to positronium energy levels

计算正电子能级的高阶修正

DOI：
10.22323/1.353.0004
发表时间：
2019
期刊：
International Conference on Precision Physics and Fundamental Physical Constants - FFK2019
影响因子：
0
作者：
Adkins, Gregory S.;Akers, Benjamin;Alam, Md Faisal;Tran, Lam M.;Zhang, Xuan
通讯作者：
Zhang, Xuan

Coulomb expectation values in D=3 and D=3−2ε dimensions

D=3 和 D=3−2π 维度中的库仑期望值