Observation of high-j quasiparticle states in Cm249 by in-beam γ-ray spectroscopy using heavy-ion transfer reactions

We have measured de-excitation γ rays in Cm249 populated by one-neutron stripping reactions with a Cm248 target and 162-MeV O16, 162-MeV O18, and 120-MeV C13 beams. γ rays in Cm249 were identified by measuring kinetic energies of outgoing particles using Si ΔE-E detectors. It was demonstrated that high-j orbitals were selectively populated in the (O16, O15) reaction having a large negative Q value. We have observed eight quasiparticle states above the deformed shell gap of N=152. The 1/2+[620], 1/2-[750], and 7/2+[613] bands were extended up to 19/2+, 19/2-, and 13/2+ states, respectively. We have established the 9/2,9/2+[615] state at 526 keV, the 9/2/2+[604] state with a short life of T1/22 ps at 1030 keV, and the 11/2,11/2-[725] state with T1/2=19(1) ns at 375 keV. Furthermore, the 17/21/2+[880] state, having a large component of the k17/2 spherical single-particle state, has been identified at 1505 keV. We discuss the properties of those quasiparticle states in the framework of a deformed shell model.