Open Access. Powered by Scholars. Published by Universities.^{®}

#
Physical Sciences and Mathematics *Commons*^{™}

Open Access. Powered by Scholars. Published by Universities.^{®}

Articles **1** - **2** of ** 2**

## Full-Text Articles in Physical Sciences and Mathematics

Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt

#### Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt

*Physics Faculty Research & Creative Works*

A comparison of precision frequency measurements to quantum electrodynamics (QED) predictions for Rydberg states of hydrogenlike ions can yield information on values of fundamental constants and test theory. With the results of a calculation of a key QED contribution reported here, the uncertainty in the theory of the energy levels is reduced to a level where such a comparison can yield an improved value of the Rydberg constant.

Relativistic Calculation Of The Two-Photon Decay Rate Of Highly Excited Ionic States, Ulrich D. Jentschura, Andrey S. Surzhykov

#### Relativistic Calculation Of The Two-Photon Decay Rate Of Highly Excited Ionic States, Ulrich D. Jentschura, Andrey S. Surzhykov

*Physics Faculty Research & Creative Works*

Based on quantum electrodynamics, we reexamine the two-photon decay of one-electron atoms. Special attention is paid to the calculation of the (two-photon) total decay rates which can be viewed as the imaginary part of the two-loop self-energy. We argue that our approach can be easily applied to the cases with a virtual state having an intermediate energy between the initial and the final state of the decay process leading, thus, to the resonance peaks in the two-photon energy distribution. In order to illustrate our approach, we obtain fully relativistic results, resolved into electric and magnetic multipole components, for the two-photon ...