Hyperfine quenching of the metastable 3P0,2 states in divalent atoms -: art. no. 042506

Hyperfine quenching rates of the lowest-energy metastable P-3(0) and P-3(2) states of Mg, Ca, Sr, and Yb atoms are computed. The calculations are carried out using ab initio relativistic many-body methods. The computed lifetimes may be useful for designing novel ultraprecise optical clocks and trapping experiments with the P-3(2) fermionic isotopes. The resulting natural widths of the P-3(0)-S-1(0) clock transition are 0.44 mHz for Mg-25, 2.2 mHz for Ca-43, 7.6 mHz for Sr-87, 43.5 mHz for Yb-171, and 38.5 mHz for Yb-173. Compared to the bosonic isotopes, the lifetime of the P-3(2) states in fermionic isotopes is noticeably shortened by the hyperfine quenching but still remains long enough for trapping experiments.