Lifetime measurement of excited states in Ce-144: Enhanced E1 strengths in a candidate for octupole deformation

A lifetime measurement of excited states in Ce-144 using the (142)ce(O-18, O-16) reaction with a beam energy of 67 MeV and the recoil distance Doppler-shift method was performed at the Cologne FN Tandem accelerator. Lifetimes of the three lowest yrast states in Ce-144 have been measured as well as for the 3(1)(-) state and an effective lifetime of the 4(2)(+) state. Reduced E2 transition strengths determined using these results have been compared to predictions from recent shell-model calculations. From the interband transitions reduced E1 strengths could be determined, which are strongly enhanced.