Loss of collectivity along the yrast line in 158Er

Abstract Lifetimes of yrast states from spin 14 through 40 have been measured in 158 Er. The Doppler-shift recoil-distance method was used in conjunction with the multi-Ge detector array HERA, and γγ coincidences were analyzed. The collectivity of the nucleus drops from 200 W.u. to 110 W.u. in the region of the second backbend. By spin 38 it has decreased further to 25 W.u., consistent with a band termination.