E2 transition rates and seniority mixing in the proton 1g [formula omitted] orbit

Abstract

The half-lives of the lowest 21 2 + states in 91Nb and 93Tc were measured with the pulsed beam direct timing method. The results are T 1 2 = 0.92 ± 0.10 ns and 1.61 ± 0.10 ns for 91Nb and 93Tc , respectively. The known experimental data on E2 transition rates in N = 50 nuclei are analysed in the light of a suggested seniority mixing in the proton 1 g 9 2 . orbit. It is concluded that the E2 matrix elements cannot be explained satisfactorily in the proton p 1 2 g 9 2 model space, even if free seniority mixing is allowed.