80 research outputs found
Collective and broken pair states of 65,67Ga
Excited states of 65Ga and 67Ga nuclei were populated through the 12C(58Ni,αp) and 12C(58Ni,3p) reactions, respectively, and investigated by in-beam γ-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and γ rays. The level schemes of 65,67Ga were constructed on the basis of γγ-coincidence relations up to 8.6 and 10 MeV excitation energy, and Iπ=27/2 and 33/2+ spin and parity, respectively. The structure of 65,67Ga nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in the boson-fermion basis states. Most of the states were assigned to quasiparticle + phonon and three quasiparticle configurations on the basis of their electromagnetic decay properties
Pronounced Shape Change Induced by Quasiparticle Alignment
Mean lifetimes of high-spin states of 74Kr have been determined using the Doppler-shift attenuation method. The high-spin states were studied using the 40Ca(40Ca,α2p) reaction at a beam energy of 160 MeV with the GASP γ-ray spectrometer. The ground-state band and negative parity side band show the presence of three different configurations in terms of transitional quadrupole deformations. A dramatic shape change was found along the ground-state band after the S-band crossing. The deduced quadrupole deformation changes are well reproduced by cranked Woods-Saxon Strutinsky calculations
Yrast level structure of the neutron-deficient N = 80 isotones 146Dy, 147Ho and 148Er up to high-spin values
High-spin level schemes of the N = 80 isotones 146Dy, 147Ho and 148Er have been investigated by in-beam \u3b3-ray spectroscopic methods using the NORDBALL Compton-suppressed multidetector array including proton and neutron selection. The projectile-target system 58Ni + 92Mo at 260 MeV beam energy has been used to produce the neutron-deficient N = 80 isotones. The previously known schemes have been extended to considerably higher spin and exitation energy, up to I = 23?, E x 48 8.9 MeV in 146Dy, I = 53/2?, E x 48 8.7 MeV in 147Ho and I = 23?, E x 48 9.6 MeV in 148Er. The results are discussed in terms of the spherical shell model. Many of the levels can be described within this framework
Gaps in the yrast level structure of the N = 50 isotones <sup>93</sup>Tc, <sup>94</sup>Ru, <sup>95</sup>Rh at high angular momentum
Yrast level structure of the neutron deficient N=49 isotones *O9*O2Tc, *O9*O3Ru, *O9*O4Rh, and *O9*O5Pd up to high angular momentum
Gaps in the yrast level structure of the N_50 isotones *O9*O3Tc, *O9*O4Ru, and *O9*O5Rh at high angular momentum
- …