Reduced transition probabilities along the yrast line in W 166

Lifetimes of excited states in the yrast band of the neutron-deficient nuclide W166 have been measured utilizing the DPUNS plunger device at the target position of the JUROGAM II γ-ray spectrometer in conjunction with the RITU gas-filled separator and the GREAT focal-plane spectrometer. Excited states in W166 were populated in the Mo92(Kr78,4p) reaction at a bombarding energy of 380 MeV. The measurements reveal a low value for the ratio of reduced transitions probabilities for the lowest-lying transitions B(E2;4+→2+)/B(E2;2+→0+)=0.33(5), compared with the expected ratio for an axially deformed rotor (B4/2 = 1.43). © 2017 American Physical Society.