Testing Quantum Electrodynamics with Exotic Atoms

Testing quantum electrodynamics in the lowest singlet states of beryllium atom

High-precision results are reported for the energy levels of $2{^1S}$ and $2{^1P}$ states of the beryllium atom. Calculations are performed using fully correlated Gaussian basis sets and taking into account the relativistic, quantum electrodynamics (QED), and finite nuclear mass effects. Theoretical predictions for the ionization potential of the beryllium ground state $75\,192.699(7) \icm$ and the $2{^1P} \rightarrow 2{^1S}$ transition energy $42\,565.441(11) \icm$ are compared to the known but less accurate experimental values. The accuracy of the four-electron computations approaches that a…

用氦电离能异常测试奇异的电子-电子相互作用

Testing Exotic Electron-Electron Interactions with the Helium Ionization-Energy Anomaly

通过分析氦电离能异常，排除了部分相互作用模型，仅剩标量介导相互作用可能，需进一步研究电子旋磁比以验证

Testing atomic wave functions in the nuclear vicinity: the hyperfine structure with empirically-deduced nuclear and quantum electrodynamic effects

Calculations of the magnetic hyperfine structure rely on the input of nuclear properties -- nuclear magnetic moments and nuclear magnetization distributions -- as well as quantum electrodynamic (QED) radiative corrections for high-accuracy evaluation in heavy atoms. The uncertainties associated with assumed values of these properties limit the accuracy of hyperfine calculations. For example, for the heavy alkali-metal atoms Cs and Fr, these uncertainties may amount collectively to almost 1\% or 2\%, respectively. In this paper we propose a method for removing the dependence of hyperfine struct…

Perspectives on testing fundamental physics with highly charged ions in Penning traps

In Penning traps electromagnetic forces are used to confine charged particles under well-controlled conditions for virtually unlimited time. Sensitive detection methods have been developed to allow observation of single stored ions. Various cooling methods can be employed to reduce the energy of the trapped particle to nearly at rest. In this review we summarize how highly charged ions offer unique possibilities for precision measurements in Penning traps. Precision atomic and nuclear masses as well as magnetic moments of bound electrons allow among others to determine fundamental constants li…

奇异氦原子精密激光光谱中的密度效应

Density effects in precision laser spectroscopy of exotic helium atoms

针对奇异氦原子，受相关光谱研究工作启发，通过从头算势能面和耦合通道量子散射计算，评估其碰撞和密度效应，研究候选亚稳态碰撞稳定性，给出压力展宽和位移系数参考值，为测定π介子和K介子质量做准备。

Testing for the Continuous Spectrum of X-Rays Predicted to Accompany the Photoejection of an Atomic Inner Shell Electron

Echoing classical physics, quantum electrodynamics predicts the release of a spectral continuum of electromagnetic radiation upon the sudden acceleration of charged particles in quantum matter. Despite apparent theoretical success in describing sister nuclear processes, known as internal bremsstrahlung, following nuclear beta decay and K capture, the situation of the photoejection of an electron from an inner shell of an atom, intraatomic bremsstrahlung (IAB), is far from settled. In this paper we present fresh measurements which rely on contemporary signal processing as well as the high flux …