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, M. Petri, K. Andgren, E. Ganioǧlu, 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, P. Rahkila, J. Sarén, C. Scholey, J. Sorri, J. Uusitalo, R. Wadsworth, R. Wyss

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

2 Citations (Scopus)

Abstract

Gamma-ray transitions have been identified for the first time in the extremely neutron-deficient Tz = 1 nuclide 110Xe 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 109I, exhibiting band structures built on g7/2 and h11/2 states in a weakly deformed, triaxial nucleus. In addition, a third band is proposed to be built on a g7/2 orbital coupled to an octupole-vibrational phonon of the 108Te core. The results were obtained in a recoil-decay tagging experiment using the 58Ni(54Fe,2n/p2n) reaction at a beam energy of 195 MeV. The experiment was performed using the highly efficient JUROGAM γ-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer. The results on 110Xe 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 106Te and 109I, showing similar trends, are also discussed.

Original languageEnglish
Title of host publicationProton Emitting Nuclei and Related Topics - International Conference, PROCON 2007
Place of PublicationCollege Park MD USA
PublisherAIP Publishing
Pages156-162
Number of pages7
Volume961
ISBN (Print)9780735404755
DOIs
Publication statusPublished - Dec 2007
Externally publishedYes
EventInternational Conference on Proton Emitting Nuclei and Related Topics, PROCON 2007 - Lisbon, Portugal
Duration: 17 Jun 200723 Jun 2007

Publication series

NameAIP Conference Proceedings
Volume961
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

ConferenceInternational Conference on Proton Emitting Nuclei and Related Topics, PROCON 2007
CountryPortugal
CityLisbon
Period17/06/0723/06/07

Keywords

  • Gamma-ray spectroscopy
  • Proton dripline
  • Recoil-decay tagging

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