High spin band structure in 139 Nd

High-spin states in 139Nd nucleus have been reinvestigated with the reaction 128Te (16O, 5n) at a beam energy of 90 MeV. The level scheme has been expanded with spin up to 47/2 . At the low spin states, the yrast collective structure built on the νh11/2-1 multiplet shows a transitional shape with γ≈ 32° according to calculations of the triaxial rotor-plus-particle model. Three collective oblate bands with γ～-60° at the high spin states were identified for the first time. A band crossing is observed around ω～0.4 MeV in one oblate band based on the 25/2-level.