Series mixing in high-L Rydberg states of H2: An experimental test of polarization-model predictions

Microwave spectroscopy of high-L (0,1)nLN Rydberg states of H2, with 26≤n≤30 is reported. The results show a strong perturbation at n=28 due to the nearly degenerate (0,3)16LN states. Mixing between members of these two Rydberg series results in energy perturbations that can be measured quite precisely (≤1%) from the microwave spectra and that are found to be in good agreement with a priori predictions based on the interseries matrix elements of the polarization potential. The connection between this use of the polarization potential and the systematic derivation of the polarization model from perturbation theory is discussed