g factor of the 12^+ K -isomer in ^174 W

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 E 2 transition to the 10^+ level of the ground state band with respect to the γ -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 ≈ 180 .