Properties of the _{69}^{150}{\text{T}}{{\text{m}}_{81}} 6− β-decaying isomer

Decay experiments for 148Ho 6− and 150Tm 6− were carried out at the GSI On-line mass separator using 5 MeV/A 58Ni-beams on 94Mo and 96Ru targets. Gammaγ-and γX-coincidences established the 150Tm 6− decay scheme, and e− gave firm Iπ assignments for 148Dy and 150Er levels fed in the decays. It was found that the previously unknown \(6_1^ -\) state in 150Er receives significant β-strength, which strongly suggests \(\pi {h_{11/2}}\nu s_{1/2}^{ - 1}\) character for the 150Tm 6− isomer. The results are discussed in terms of the expected GT strength function. Shell model calculations for the \(\pi h_{11/2}^4\) yrast states are presented.