Study On High-Spin Statesin Neutron-Rich¹⁰⁴Zr,¹¹⁴Ru And Neutron-Deficient¹³⁹Pr Nuclei

High-spin states of neutron-rich¹⁰⁴Zr,¹¹⁴Ru and neutron-deficient¹³⁹Pr nuclei havebeen studied in order to deeply understand the characteristics of the nuclear structure,nuclear shape, nuclear force, and so forth.The experiment of¹⁰⁴Zr and¹¹⁴Ru nuclei was done at the Lawrence BerkeleyNational Laboratory in U.S.A. The emissions of prompt γ-rays in spontaneous fission of252Cf were measured by the Gammasphere detector array. The Gammasphere detectorarray was built up with102Compton-suppressed High Purity Germanium detectors. Athree-dimensional histogram was created. The experiment of¹³⁹Pr was performed atHI-13Tandem Accelerator in China Institute of Atomic Energy. The high-spin states of¹³⁹Pr were populated via the heavy ion fusion-evaporation reaction124Sn （19F,4n） withbeam energy of80MeV. The two-or higher-coincidence events were recorded and atotal of5.2×10⁷coincidence events were collected. A γ-γ coincidence matrix and twoDCO matrices were constructed.In¹⁰⁴Zr, a new sideband has been identified with bandhead energy at1928.7keV.We analyzed this band structure using systematics comparison. This band structure wasalso investigated by projected shell model calculations. The calculated levels are ingood agreement with the experiment data and suggest that this band is based on theneutronν5/2-[532] ν3/2⁺[411] configuration.In¹¹⁴Ru, the ground-state band as well as the one-phonon γ-vibrational band hasbeen extended, and two new levels are proposed as the members of two-phononγ-vibrational band. At the rotational frequency ω≈0.4MeV, a back bending has beenobserved in the ground-state band. By using the triaxial deformation paremeters, thecranking shell model calculations indicated that the back bending in¹¹⁴Ru shouldoriginate from the alignment of a pair of h11/2neutrons. While the calculations for theγ-vibrational band structures by using triaxial projected shell model are in goodagreement with the experiment data. But by using oblate deformation parameters, bothcalculated results are not in agreement with the experimental data. This indicates thatthe¹¹⁴Ru is with the triaxial deformation.In¹³⁹Pr, the level scheme has been extensively expanded compared to the previous results.Four collective band structures at high spin states have been newly identified.From systematics analysis, one of the bands is proposed as a decoupled band; two bandsare proposed as oblate bands with γ^-60; another band is suggested as aoblate-triaxialband withγ^-90. The possible configurations for these bands have been discussed.