Observation of a Collective Oblate Band in 137Ce

摘要

High spin states in 137 Ce have been studied by using the heavy-ion induced reaction 124Sn(18 O, 5n) carried out at rnChina Institute of Atomic Energy. Partial level scheme with spin up to (43/2-), including a high spin collective rnrotational band observed for the first time, has been established. The collective band shows the properties similar rnto those oblate bands with γ ～-60° in neighboring nuclei and probably originates from the five quasi-particle rnconfiguration νs1/2 [vh11/2]2 π97/2 πh11/2. The characteristics of this oblate band have been discussed.