Band-like structures in97Ru

Abstract
The 88Sr(12C, 3n gamma ) reaction is used to populate high-spin states in the nucleus 97Ru. Gamma-ray excitation functions, angular distribution and recoil-distance measurements are used to determine branching ratios, multipolarities and lifetimes of the electromagnetic decays of these states. The lifetimes of the states at 2739.4, 2545.7, 1845.9, 1199.3, 879.1 and 421.6 keV have been determined for the first time as tau =12500+or-1300, <5, 21+or-3, 5+or-1, approximately=5 and 50+or-3 ps respectively. Some level sequences with Delta I=2 (band-like structures) are observed with relatively large 'intraband' B(E2) values as well as smaller B(E2) transition rates and hindered M1 transitions between 'bands'. The results are discussed in terms of current nuclear models.
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