Spectroscopy of Radiative Decay Processes in Heavy Rydberg Alkali Atomic Systems

We present the results of studying the radiation decay processes and computing the probabilities and oscillator strengths of radiative transitions in spectra of heavy Rydberg alkali-metal atoms. All calculations of the radiative decay (transitions) probabilities have been carried out within the generalized relativistic energy approach (which is based on the Gell-Mann and Low S-matrix formalism) and the relativistic many-body perturbation theory with using the optimized one-quasiparticle representation and an accurate accounting for the critically important exchange-correlation effects as the perturbation theory second and higher orders ones. The precise data on spectroscopic parameters (energies, reduced dipole transition matrix elements, amplitude transitions) of the radiative transitions nS_1/2→n′P_1/2,3/2 (n = 5, 6; n′ = 10–70), nP_1/2,3.2→n′D_3/2,5/2 (n = 5, 6; n′ = 10–80) in the Rydberg Rb, Cs spectra and the transitions 7S_1/2-nP_1/2,3/2, 7P_1/2,3.2-nD_3/2,5/2 (n = 20–80) in the Rydberg francium spectrum are presented. The obtained results are analyzed and discussed from viewpoint of the correct accounting for the relativistic and exchange-correlation effects. It has been shown that theoretical approach used provides an effective accounting of the multielectron exchange-correlation effects, including effect of essentially non-Coulomb grouping of Rydberg levels and others.