Competition between collective oblate rotation and non-collective prolate K isomerism in neutron-rich tungsten isotopes

Abstract

Recent experiments open up the possibility to investigate oblate rotation-aligned states and prolate high-K isomers in neutron-rich tungsten isotopes. In the present work, we perform the projected-shell-model calculations for A ∼ 190 tungsten nuclei. The 190W results are compared with experimental data. The observed 8+ isomer is assigned as a two-quasiproton Kπ = 8+ configuration. Low-lying high-K four-quasiparticle states are predicted. Of particular interest is the prediction of the Kπ = 20+ state in 190,192W, which may form a long-lived spin trap. In competition with the prolate high-K states, rotational alignment leads to near-yrast collective oblate rotation.