G factor of the $$12^+$$ K-isomer in $$^{174}$$W

Abstract

The g factor of the $$12^+$$ K-isomer in $$^{174}$$ W has been measured by means of the time-differential perturbed angular distribution technique as $$g(12^+)=+0.304(11)$$ . In addition, the half-life of the isomer has been remeasured as $$T_{1/2}(12^+)=124(8)$$ ns, in agreement with the literature value and confirming the anomalous hindrance F of the E2 transition to the $$10^+$$ level of the ground state band with respect to the $$\gamma $$ -tunnelling model prediction. The measured g factor has been compared with estimates based on experimental g factors from odd-mass isotopes in the same mass region and with Nilsson model calculations. The results establish unique features of the $$12^+$$ K-isomer in $$^{174}$$ W, which can possess a non-pure intrinsic configuration and/or can be characterised by values of the intrinsic quadrupole moment $$Q_0$$ and the rotational g factor $$g_R$$ significantly different with respect to the majority of K-isomers at mass $$A \approx 180$$ .