Static Quadrupole Moment of the Five-Quasiparticle K=35/2 Isomer in ¹⁷⁹W Studied with the Level-Mixing Spectroscopy Method

The spectroscopic quadrupole moment of the high-spin, high-K five-quasiparticle isomer (K^π=[(35^-)/2], T_1/2=750(80) ns, E_i = 3349 keV) in ¹⁷⁹W has been determined using the level mixing spectroscopy method.
A value Q_s = 4.00([(+0.83) || (-1.06)])e b was derived, which corresponds to an intrinsic quadrupole moment Q₀ = 4.73([(+0.98) || (-1.25)])e b and to a quadrupole deformation β₂ = 0.185([(+0.038) || (-0.049)]).
These values differ significantly from the deduced ground-state quadrupole moments and are in disagreement with the current theoretical predictions in this mass region.