Core-valence correlation effects onE1 andE2 decay rates inCa+

Abstract

Elaborate multiconfiguration Hartree-Fock wave functions have been obtained for the 4s ${}_{}{}^2{}_{}{}^{}$S, 3d ${}_{}{}^2{}_{}{}^{}$D, and 4p ${}_{}{}^2{}_{}{}^{}$P° states in ${\mathrm{Ca}}^{+}$ in order to investigate the core-valence correlation effects on the transition probabilities of the electric dipole (E1) and quadrupole (E2) processes involving these levels. In parallel, model-potential calculations using a core-polarization potential have been performed. They support the large reduction of the oscillator strengths found in the ab initio approach for both the E1 and E2 processes. The agreement between the two sets of results is satisfactory only if the polarization term is included in the Hartree-Fock variational procedure. The present theoretical ${}_{}{}^2{}_{}{}^{}$P${\mathrm{°}}_{1/2,3/2}$ lifetime values differ by 3.5% from the most recent fast-beam laser measurements with an estimated single-standard-deviation uncertainty of about 1%.