Monopole transitions in <sup>172</sup>Yb and the nature of the 1405 keV 0<sup>+</sup> level
A R H Subber; W D Hamilton; P Van Isacker; K Schreckenbach; G Colvin; A R H Subber; Sch. of Math. & Phys. Sci., Sussex Univ., Brighton, UK; W D Hamilton; Sch. of Math. & Phys. Sci., Sussex Univ., Brighton, UK; P Van Isacker; Sch. of Math. & Phys. Sci., Sussex Univ., Brighton, UK; K Schreckenbach; Sch. of Math. & Phys. Sci., Sussex Univ., Brighton, UK; G Colvin; Sch. of Math. & Phys. Sci., Sussex Univ., Brighton, UK
Журнал:
Journal of Physics G: Nuclear Physics
Дата:
1988-01-01
Аннотация:
Measurements of the internal conversion electron spectrum and the identification of EO transitions linking the excited O<sup>+</sup> states in <sup>172</sup>Yb provide new information on the level structure of this nucleus. The (n,e<sup>-</sup>) reaction with a Yb<sub>2</sub>O<sub>3</sub> target enriched in <sup>171</sup>Yb was used and all possible EO transitions were searched for. Several new low-energy EO transitions were observed and evidence was found for a new 0<sup>+</sup> level at 1920 keV. This may be due to pair excitation, which is also a possible explanation for the 1405 keV 0<sup>+</sup> level. The authors show that an alternative explanation for the 1405 keV level is that it is the head of a K<sup>pi </sup>=0<sup>+</sup> mixed symmetry band with band members at 1477 keV (2<sup>+</sup>) and 1633 keV (4<sup>+</sup>). The level energies, B(E2) values, multipole mixing ratios and X values are compared with the predictions of the DDM and the IBA-2.
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