Simple mode on a highly excited background: Collective strength and damping in the continuum
- Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russia)
- Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States)
Simple states, such as isobaric analog states or giant resonances, embedded into continuum are typical for mesoscopic many-body quantum systems. Due to the coupling to compound states in the same energy range, a simple mode acquires a damping width ({open_quotes}internal{close_quotes} dynamics). When studied experimentally with the aid of various reactions, such states reveal enhanced cross sections in specific channels at corresponding resonance energies ({open_quotes}external{close_quotes} dynamics which include direct decay of a simple mode and decays of intrinsic compound states through their own channels). We consider the interplay between internal and external dynamics using a general formalism of the effective non-Hermitian Hamiltonian and looking at the situation both from the {open_quotes}inside{close_quotes} (strength functions and spreading widths) and from the {open_quotes}outside{close_quotes} (S matrix, cross sections, and delay times). The restoration of isospin purity and the disappearance of the collective strength of giant resonances at high excitation energy are discussed as important particular manifestations of this complex interplay. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 531919
- Journal Information:
- Physical Review, C, Journal Name: Physical Review, C Journal Issue: 1 Vol. 56; ISSN 0556-2813; ISSN PRVCAN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Properties of the giant dipole resonance built on the isobaric analog state
Continuum shell model