Isobar production in heavy ion collisions
The production of isobars with concomitant giant resonance excitations due to peripheral collisions of relativistic heavy ions is investigated. The interaction is described by a modified form of the one-pion exchange potential (OPEP) where the projectile ordinary spin operator is replaced by a transition spin operator which describes the creation of an isobar from a nucleon. The scattering is analyzed using time-dependent harmonic perturbation theory to determine the reaction total cross sections. The results obtained, which are valid for rections involving self-conjugate nuclei, are applied to the specific collision of 2.1 GeV/nucleon /sup 16/O projectiles with /sup 12/C targets at rest. Cross sections are investigated using two different models for the nuclear spin states. In the first model, the many-body nuclear spin state is reduced, in the spirit of a particle-hole state, to an equivalent two-body state called a particle-core state. With this model, the total cross sections for two reactions are determined. In the first, a single isobar is formed in the projectile while the target is excited to one of its isovector J/sup ..pi../ = 1/sup +/ excited states near 15 MeV via the collective spin giant resonance mechanism. In the second, the target is excited to this same state again, and the projectile, by analogy, is assumed excited to a collective isobar giant resonance state. The calculations for the two reactions are repeated, with comparable results, for a nuclear spin model where the many-body spin states are described by unsymmetrized products of individual particle spins. In the second set of calculations, the /sup 12/C target is assumed to be excited to its isoscaler J/sup ..pi../ = 1/sup +/ state at 12.7 MeV by the spin giant resonance mechanism. Properties of the spin giant resonance and isobar giant resonance states are investigated. Finally, isobar decay and isobar/pion absorption effects are discussed.
- Research Organization:
- Idaho Univ., Moscow (USA)
- OSTI ID:
- 6291590
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON 12
ISOBARIC NUCLEI
CARBON 12 TARGET
OXYGEN 16 REACTIONS
INELASTIC SCATTERING
GIANT RESONANCE
HEAVY ION REACTIONS
NUCLEAR MODELS
OPE MODEL
TOTAL CROSS SECTIONS
BOSON-EXCHANGE MODELS
CARBON ISOTOPES
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
EVEN-EVEN NUCLEI
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NUCLEAR REACTIONS
NUCLEI
OBE MODEL
PARTICLE MODELS
PERIPHERAL MODELS
RESONANCE
SCATTERING
STABLE ISOTOPES
TARGETS
651315* - Nuclear Properties & Reactions
A=6-19
Theoretical- Nuclear Reactions & Scattering- (-1987)
651313 - Nuclear Properties & Reactions
A=6-19
Theoretical- Energy Levels & Transitions- (-1987)