Original scientific paper
β-y vibrations and SU3 symmetry in the fermion dynamical symmetry model
Cheng-Li Wu
; Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200; Department of Physics and Atmospheric Science, Drexel University, Philadelphia, Pennsylvania 19104-9984, USA
Mike W. Guidry
; Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200, USA
Da Hsuan Feng
; Department of Physics and Atmospheric Science, Drexel University, Philadelphia, Pennsylvania 19104-9984, USA
Jin Quan Chen
; Department of Physics and Atmospheric Science, Drexel University, Philadelphia, Pennsylvania 19104-9984, USA
Abstract
In addition to the previously established equivalence between the Fermion Dynammical Symmetry Model (FDSM) and the particle-rotor model, it is found that different β-y vibrational states in the geometrical description correspond to different SU3 representations in the FDSM, and that there is a one-to-one correspondence between β-y vibration quantum numbers (nβ, ny, K) and the SU3 quantum numbers (λ, μ, x). It is shown that the excitation energy associated with the SU3 Casimir operator can be written as hω (ny + nβ + K/2) x (1 + 0 ( 1/n1)), where n1 is the number of particles in the normal-parity valence levels. In the large n1 limit, this becomes identical to the geometrical results, provided the β-y vibrational frequency now is given as hω = 3B2n1, where B2 is the strength of the n-p quadrupole-quadrupole interactions. Experimental data for the first β- and y-band band-head energies in the actinide region seem to support this identification. The sudden drop of the first y-band band-head for N > 151 nuclei provides additional evidence for the dynamical Pauli effect predicted by the FDSM.
Keywords
Hrčak ID:
332146
URI
Publication date:
5.2.1990.
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