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

Journal Article · Fri Nov 30 04:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2827249· OSTI ID:21039454

Cederwall, B; Hadinia, B; Sandzelius, M; Andgren, K; Khaplanov, A; Wyss, R ^[1]; Paul, E S; Petri, M; Darby, I G; Dimmock, M R; Joss, D T; Nelson, L; Page, R D ^[2]; Ganioalu, E ^[3]; Eeckhaudt, S; Grahn, T; Greenlees, P T; Jones, P M; Julin, R; Juutinen, S ^[4]

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1. Department of Physics, Royal Institute of Technology, S-10691 Stockholm (Sweden)
2. Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom)
3. Science Faculty, Physics Department, Istanbul University, 34459 Istanbul (Turkey)
4. Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland)

Gamma-ray transitions have been identified for the first time in the extremely neutron-deficient T{sub z} = 1 nuclide {sup 110}Xe 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{sub z} = 3/2 nuclide {sup 109}I, exhibiting band structures built on g{sub 7/2} and h{sub 11/2} states in a weakly deformed, triaxial nucleus. In addition, a third band is proposed to be built on a g{sub 7/2} orbital coupled to an octupole-vibrational phonon of the {sup 108}Te core. The results were obtained in a recoil-decay tagging experiment using the {sup 58}Ni({sup 54}Fe,2n/p2n) reaction at a beam energy of 195 MeV. The experiment was performed using the highly efficient JUROGAM {gamma}-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer. The results on {sup 110}Xe establish a breaking of the normal trend of increasing first excited 2{sup +} and 4{sup +} 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 {sup 106}Te and {sup 109}I, showing similar trends, are also discussed.

• OSTI ID: 21039454
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 961; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
EXCITED STATES
GAMMA SPECTROSCOPY
GROUND STATES
IODINE 109
IRON 54
MEV RANGE
NEUTRONS
NICKEL 58
NUCLEAR DECAY
OCTUPOLES
PHONONS
PROTON-NEUTRON INTERACTIONS
PROTONS
RECOILS
TELLURIUM 106
TELLURIUM 108
XENON 110