Observation of the 1{sup +} scissors mode in the {gamma}-soft nucleus {sup 134}Ba
- Institut fuer Strahlenphysik, Universitaet Stuttgart, 70569 Stuttgart (Germany)
A photon scattering experiment was performed on the {gamma}-soft nucleus {sup 134}Ba with photon energies of {ital E}{sub {gamma}}{lt}4.1. Around 3 MeV excitation energy a fragmented 1{sup +} scissors mode as well as the (2{sup +}{circle_times}3{sup {minus}}){sub 1{sup {minus}}} two-phonon dipole state were identified. The dipole excitation strengths were measured. The excitation strength of the scissors mode in this {gamma}-soft nucleus is well reproduced by an empirical {ital M}1 sum rule that generalizes the {open_quote}{open_quote}{delta}{sup 2} law{close_quote}{close_quote} to nuclei without axial symmetry. The IBM-2 describes the mixed-symmetry states in {sup 134}Ba and their decay pattern. A large {ital E}2/{ital M}1 mixing ratio for the 1{sup +}{r_arrow}2{sup +}{sub 1} decay of the scissors mode to the 2{sup +}{sub 1} state is predicted by the IBM-2. The new result from {sup 134}Ba together with a similar previous observation in {sup 196}Pt corroborates the scissors mode as a typical excitation mode of {gamma}-soft nuclei. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Yale University
- DOE Contract Number:
- FG02-91ER40609
- OSTI ID:
- 389470
- Journal Information:
- Physical Review, C, Journal Name: Physical Review, C Journal Issue: 5 Vol. 54; ISSN PRVCAN; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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