Proton-neutron structure of low lying collective quadrupole excitations inXe-126

Citation
A. Gade et al., Proton-neutron structure of low lying collective quadrupole excitations inXe-126, NUCL PHYS A, 665(3-4), 2000, pp. 268-284
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
NUCLEAR PHYSICS A
ISSN journal
0375-9474 → ACNP
Volume
665
Issue
3-4
Year of publication
2000
Pages
268 - 284
Database
ISI
SICI code
0375-9474(20000228)665:3-4<268:PSOLLC>2.0.ZU;2-W
Abstract
Low spin states of the nucleus (126) Xc were studied by means of gamma-spec troscopy using the fusion evaporation reaction Te-123(alpha,n)Xe-126 perfor med at the Cologne FN TANDEM accelerator. The gamma gamma coincidence and s ingles spectra were measured with the OSIRIS-cube spectrometer. Beside the ground and quasi-gamma bands many ther low lying states were observed. gamm a gamma directional correlations from oriented states (DCO) were analyzed t o determine the multipolarities of the gamma-transitions. We observed domin ant E2-transitions in the quasi-gamma band and from the gamma- to the groun d band but also a large M1-fraction in the 6(2)(+) -> 6(1)(+) transition. W e additionally found a strong M1-decay depopulating the 2(4)(+)-state at 20 64 keV. The lifetime of this state was measured using the Doppler shift att enuation technique. The experimental data are compared with a calculation u sing the proton-Neutron Interacting Boson Model (IBM-2). Good agreement is reached in the vicinity of the O(6)-limit. The observed M1-transition of th e 2(4)(+) state is interpreted as due to a fragment of the lowest 2(+) mixe d-symmetry state predicted by the IBM-2. (C) 2000 Elsevier Science B.V. All rights reserved.