Fundamental Constants and Tests of Theory in Rydberg States of Hydrogenlike Ions

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.

Figure 1

Graph showing values of $Z$ and approximate $n$ that give a specified value of the frequency for transitions between states with principal quantum number $n$ and $n-1$ in a hydrogenlike ion with nuclear charge $Z$. Frequencies in the near-infrared and visible range are indicated in color.