Observation of the 1{sup +} scissors mode in the {gamma}-soft nucleus {sup 134}Ba

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.54.R2129· OSTI ID:389470

Maser, H; Pietralla, N; von Brentano, P; Herzberg, R; Kneissl, U; Margraf, J; Pitz, H H; Zilges, A ^[1]

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1. 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

Related Subjects

66 PHYSICS
BARIUM 134
BARIUM 134 TARGET
DIPOLES
EXCITATION
MIXING RATIO
NUCLEAR FRAGMENTS
PHONONS
PHOTONUCLEAR REACTIONS
SUM RULES