Testing mean-field models near the N=Z line: gamma-ray spectroscopy of the T-z=1/2 nucleus Kr-73
2002 (English)In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 65, no 4Article in journal (Refereed) Published
Excited states in the N=Z+1 nucleus Kr-73 have been investigated using the Ca-40(Ar-36,2pn) and Ca-40(Ca-40,alpha2pn) reactions at 145 and 160 MeV, respectively. gamma rays were detected using the Gammasphere array and events were recorded in coincidence with charged-particle and neutron detectors. The three previously observed bands were extended to high spin, and a new unfavored positive-parity band has been observed. The alignment characteristics and decay properties of the bands are all consistent with large-deformation prolate rotation, with no clear evidence for oblate bands or shape coexistence. This is quite different from neighboring Kr-72,Kr-74, indicating a strong shape-stabilizing role for the valence neutron. The experimental results are compared to extended total Routhian surface, cranked Nilsson Strutinsky, and cranked relativistic mean-field calculations. The results suggest that the paired calculations lack some important physics. Neutron-proton correlations may be the missing ingredient. There is also evidence for an unusual band crossing in the negative-parity bands, which may indicate the presence of T=0 pairing correlations. At high spin all the models can reproduce the experimental data.
Place, publisher, year, edition, pages
2002. Vol. 65, no 4
= z nuclei, oblate shape-coexistence, rotational bands, mass region, high-spin, states, t=0, identification, alignment, collectivity
IdentifiersURN: urn:nbn:se:kth:diva-21489DOI: 10.1103/PhysRevC.65.044331ISI: 000175186200052OAI: oai:DiVA.org:kth-21489DiVA: diva2:340187
QC 201005252010-08-102010-08-10Bibliographically approved