A truncated spherical shell model for nuclear collective excitations: Applications to the odd-mass systems, neutron-proton systems, and other topics
One of the most elusive quantum system in nature is the nucleus, which is a strongly interacting many body system. In the hadronic (a la neutrons and protons) phase, the primary concern of this thesis, the nucleus' single particle excitations are intertwined with their various collective excitations. Although the underpinning of the nucleus is the spherical shell model, it is rendered powerless without a severe, but intelligent truncation of the infinite Hilbert space. The recently proposed Fermion Dynamical Symmetry Model (FDSM) is precisely such a truncation scheme and in which a symmetry-dictated truncation scheme is introduced in nuclear physics for the first time. In this thesis, extensions and explorations of the FDSM are made to specifically study the odd mass (where the most intricate mixing of the single particle and the collective excitations are observed) and the neutron-proton systems. In particular, the author finds that the previously successful phenomenological particle-rotor-model of the Copenhagen school can now be well understood microscopically via the FDSM. Furthermore, the well known Coriolis attenuation and variable moment of inertia effects are naturally understood from the model as well. A computer code FDUO was written by one of us to study, for the first time, the numerical implications of the FDSM. Several collective modes were found even when the system does not admit a group chain description. In addition, the code is most suitable to study the connection between level statistical behavior (a at Gaussian Orthogonal Ensemble) and dynamical symmetry. It is found that there exist critical region of the interaction parameter space were the system behaves chaotically. This information is certainly crucial to understanding quantum chaotic behavior.
- Research Organization:
- Drexel Univ., Philadelphia, PA (USA)
- OSTI ID:
- 6092541
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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NUCLEAR MODELS
COLLECTIVE EXCITATIONS
F CODES
HADRONS
HILBERT SPACE
MANY-BODY PROBLEM
MASS
PARITY
QUANTUM MECHANICS
SHELL MODELS
SYMMETRY
BANACH SPACE
COMPUTER CODES
ELEMENTARY PARTICLES
ENERGY-LEVEL TRANSITIONS
EXCITATION
MATHEMATICAL MODELS
MATHEMATICAL SPACE
MECHANICS
PARTICLE PROPERTIES
SPACE
653001* - Nuclear Theory- Nuclear Structure
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