Sr5pnd J=3autoionizing series and interference of excitation due to bound-state perturbation

Using the isolated-core-excitation method we have measured the energies and widths of the three Sr J=3 autoionizing 5pnd Rydberg series for n=11–36. We have fitted our data to a six-channel multichannel quantum-defect theory model reproducing the observed energies, widths, and interactive excitation spectra for the three series. In addition, the effect of the bound 4d6s ${\mathrm{}}^1$ $D_2$ and 4d6s ${}^3$ $D_2$ perturbers, which mix the bound 5snd ${}_{}{}^1{}_{}{}^{}\mathrm{D}_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{D}_2^{}{}_{}{}^{}$ states, on the excitation spectra has been observed and accounted for.