Skins and halos in exotic nuclei
- Argonne National Laboratory, IL (United States)
Radioactive beam experiments have made it possible to study, the properties of nuclei far from the beta-stability line. The most detailed studies have been performed with light neutron-rich nuclei. The weak binding allows the valence neutrons to form an extended density tail, a so-called neutron halo or skin. It also permits a new low-lying mode of electric dipole excitation associated with the relative motion of the valence neutrons and the core. The principal experimental evidence for these features is unusually large breakup cross sections. Another characteristic feature is that nuclei which are at the edge of the neutron drip line contain an even number of neutrons whereas neighboring odd-N isotopes are often particle unstable. This implies that pair interactions between the valence neutrons play a crucial role for the binding. Examples of nuclei that exhibit all of these features, and which have been studied in the greatest detail, are {sup 6}He, {sup 11}Li and {sup 14}Be. The neutron skin or halos consist in these cases of two valence neutrons interacting with a more tightly bound core. This makes them suitable for theoretical studies in terms of three-body models. An example of a nucleus which contains a single-neutron halo is {sup 11}Be. It has also been studied in breakup reactions, and its structure is of particular interest because of the ground-state parity inversion, which has been a theoretical problem for many years. The status and interpretations of experimental and theoretical studies of nuclei close to the neutron drip line will be reviewed.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 387093
- Report Number(s):
- CONF-931044-; ISSN 0003-0503; TRN: 96:027033
- Journal Information:
- Bulletin of the American Physical Society, Vol. 38, Issue 9; Conference: Fall meeting of the Division of Nuclear Physics of the American Physical Society, Pacific Grove, CA (United States), 20-23 Oct 1993; Other Information: PBD: Oct 1993
- Country of Publication:
- United States
- Language:
- English
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