Observation of high-spin oblate band structures in 141Pm

The high-spin states of Pm-141 have been investigated through the reaction Te-126(F-19, 4n) at a beam energy of 90 MeV. A previous level scheme has been updated with spins up to 49/2h. Six collective bands at high spins are newly observed. Based on the systematic comparison, one band is proposed as a decoupled band; two bands with strong Delta I = 1 M1 transitions inside the bands are suggested as the oblate bands with gamma similar to-60 degrees; three other bands with large signature splitting have been proposed with the oblate-triaxial deformation with gamma similar to-90 degrees. The triaxial n-particle-n-hole particle rotor model calculations for one of the oblate bands in Pm-141 are in good agreement with the experimental data. The other characteristics for these bands have been discussed.