Relativistic transition probabilities and lifetimes of low-lying levels in ytterbium

Multiconfiguration Dirac-Fock calculations of E1, E2, M1 and M2 transition probabilities and lifetimes for the low-lying levels of neutral ytterbium are reported. For E1 transitions the valence-core electron correlations are also included in the core-polarization model. In particular, the lifetimes of the 6s6p 1 P 1 and 3 P 1 states, when corrected for core polarization, are 4.78 ns and 1294 ns, respectively. The lifetime of the metastable 6s6p 3 P 2 state is calculated to be 14.5 s.