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 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 Q0 and the rotational g factor gR significantly different with respect to the majority of K-isomers at mass A ≈ 180.