Lifetimes and branching ratios of excited states in La^-, Os^-, Lu^-, Lr^-, and Pr^-

Relativistic configuration-interaction calculations have been performed for all possible E1, M1, and E2 transitions between bound anion states of La^- and Os^-. We pay particular attention to E1 transitions in each case that may be of use in laser cooling of these anions. Although the La^- transition energy is approximately one-third of the Os^- transition, our results indicate that the Einstein A coefficient is nearly two orders of magnitude larger, which would lead to more efficient laser cooling. We have also explored long-lived opposite-parity excited states in Lu^- and Lr^- which are restricted to M2 decay by selection rules. Finally, in Pr^-, we find sufficient mixing between a weakly bound excited 4f²5d²6s² state with a nearby 4f³6s²6p resonance to result in a lifetime similar to that of the other excited anion states, despite the fact that the dominant configurations of these M1 and E2 transitions differ by two electrons.