Electromagnetic strength of neutron and proton single-particle halo nuclei
| Autor: | Stefan Typel, Gerhard Baur |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
halo nuclei
Nuclear and High Energy Physics sum rules Nuclear Theory Extrapolation FOS: Physical sciences Zero-point energy Nuclear Theory (nucl-th) Nuclear physics scaling laws Coulomb medicine ddc:530 Neutron Nuclear Experiment (nucl-ex) Nuclear Experiment Scaling effective-range approximation Physics ANC method radiative capture final-state interaction medicine.anatomical_structure electromagnetic transitions Halo Atomic physics Nucleon Nucleus |
| Zdroj: | Nuclear physics / A 759, 247-308 (2005). doi:10.1016/j.nuclphysa.2005.05.145 |
| ISSN: | 0375-9474 |
| DOI: | 10.1016/j.nuclphysa.2005.05.145 |
| Popis: | Electromagnetic strength functions of halo nuclei exhibit universal features that can be described in terms of characteristic scale parameters. For a nucleus with nucleon+core structure the reduced transition probability, as determined, e.g., by Coulomb dissociation experiments, shows a typical shape that depends on the nucleon separation energy and the orbital angular momenta in the initial and final states. The sensitivity to the final-state interaction (FSI) between the nucleon and the core can be studied systematically by varying the strength of the interaction in the continuum. In the case of neutron+core nuclei analytical results for the reduced transition probabilities are obtained by introducing the effective-range expansion. The scaling with the relevant parameters is found explicitly. General trends are observed by studying several examples of neutron+core and proton+core nuclei in a single-particle model assuming Woods-Saxon potentials. Many important features of the neutron halo case can be obtained from a square-well model. Rather simple analytical formulas are found. The nucleon-core interaction in the continuum affects the determination of astrophysical S factors at zero energy in the method of asymptotic normalisation coefficients (ANC). It is also relevant for the extrapolation of radiative capture cross sections to low energies. Comment: 77 pages, 25 figures, 7 tables, accepted for publication in Nucl. Phys. A |
| Databáze: | OpenAIRE |
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