Evidence for enhanced collectivity in Te-I-Xe nuclei near the N=Z=50 double shell closure

B. Cederwall*, B. Hadinia, M. Sandzelius, E. S. Paul, A. Petri, K. Andgren, E. Ganioglu, I. G. Darby, M. R. Dimmock, S. Eeckhaudt, T. Grahn, P. T. Greenlees, E. Ideguchi, P. M. Jones, D. T. Joss, R. Julin, S. Juutinen, A. Khaplanov, M. Leino, L. NelsonM. Niikura, M. Nyman, R. D. Page, J. Pakarinen, Marina Petri, P. Rahkila, J. Saren, C. Scholey, J. Sorri, J. Uusitalo, R. Wadsworth, R. Wyss

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Gamma-ray transitions have been identified for the first time in the extremely neutron-deficient T-z = 1 nuclide Xe-110 and the energies of the three lowest excited states in the ground-state band have been deduced. A level scheme has also been constructed for the proton-unbound, T-z = 3/2 nuclide I-109, exhibiting band structures built on g(7/2) and h(11/2) states in a weakly deformed, triaxial nucleus. In addition, a third band is proposed to be bui It oil a g(7/2) orbital coupled to an octupole-vibrational phonon of the Te-108 core. The results were obtained in a recoil-decay tagging experiment using the Ni-58(Fe-54,2n/p2n) reaction at a beam energy of 195 MeV. The experiment was performed using the highly efficient JUROGAM y-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT focal -plane spectrometer. The results on Xe-110 establish a breaking of the normal trend of increasing first excited 2(+) and 4(+) level energies as a function of decreasing neutron number as the N = 50 major shell gap is approached for the neutron-deficient Xe isotopes. This unusual feature is suggested to be an effect of enhanced collectivity, possibly arising from isoscalar n-p interactions becoming increasingly important close to the N = Z line. Features in the low-lying levels of Te-106 and I-109, showing similar trends, are also discussed.

Original languageEnglish
Title of host publicationPROTON EMITTING NUCLEI AND RELATED TOPICS
EditorsLS Ferreira, P Arumugam
Place of PublicationMELVILLE
PublisherAmerican Institute of Physics
Pages156-162
Number of pages7
ISBN (Print)978-0-7354-0475-5
Publication statusPublished - 2007
EventInternational Conference on Proton Emitting Nuclei and Related Topics - Lisbon, Portugal
Duration: 17 Jun 200723 Jun 2007

Publication series

NameAIP CONFERENCE PROCEEDINGS
PublisherAMER INST PHYSICS
Volume961
ISSN (Print)0094-243X

Conference

ConferenceInternational Conference on Proton Emitting Nuclei and Related Topics
Country/TerritoryPortugal
CityLisbon
Period17/06/0723/06/07

Keywords

  • STATES
  • proton dripline
  • DEFORMATION
  • recoil-decay tagging
  • gamma-ray spectroscopy
  • EVEN-EVEN NUCLEI

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