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Title: Study of exotic nuclei around the 'island of inversion'

Abstract

No abstract prepared.

Authors:
; ;  [1]; ; ; ; ; ; ; ; ;  [2]; ; ; ; ; ; ; ;  [3]
  1. Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, Debrecen H-4001 (Hungary)
  2. University of Tokyo, Tokyo 1130033 (Japan)
  3. The Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan) (and others)
Publication Date:
OSTI Identifier:
21056730
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 891; Journal Issue: 1; Conference: 6. Symposium on nuclear physics, Tours (France), 5-8 Sep 2006; Other Information: DOI: 10.1063/1.2713508; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; FLUORINE ISOTOPES; GAMMA SPECTROSCOPY; LIGHT NUCLEI; MAGNESIUM ISOTOPES; NEON ISOTOPES; PROTON REACTIONS; PROTON-NUCLEON INTERACTIONS; RADIOACTIVE ION BEAMS; SODIUM ISOTOPES

Citation Formats

Elekes, Z., Dombradi, Zs., Fueloep, Zs., Saito, A., Baba, H., Iwasaki, H., Notani, M., Ohnishi, T. K., Ong, H. J., Sakurai, H., Shimoura, S., Tamaki, M., Aoi, N., Imai, N., Ishihara, M., Kishida, T., Kubo, T., Michimasa, S., Minemura, T., and Motobayashi, T.. Study of exotic nuclei around the 'island of inversion'. United States: N. p., 2007. Web. doi:10.1063/1.2713508.
Elekes, Z., Dombradi, Zs., Fueloep, Zs., Saito, A., Baba, H., Iwasaki, H., Notani, M., Ohnishi, T. K., Ong, H. J., Sakurai, H., Shimoura, S., Tamaki, M., Aoi, N., Imai, N., Ishihara, M., Kishida, T., Kubo, T., Michimasa, S., Minemura, T., & Motobayashi, T.. Study of exotic nuclei around the 'island of inversion'. United States. doi:10.1063/1.2713508.
Elekes, Z., Dombradi, Zs., Fueloep, Zs., Saito, A., Baba, H., Iwasaki, H., Notani, M., Ohnishi, T. K., Ong, H. J., Sakurai, H., Shimoura, S., Tamaki, M., Aoi, N., Imai, N., Ishihara, M., Kishida, T., Kubo, T., Michimasa, S., Minemura, T., and Motobayashi, T.. Mon . "Study of exotic nuclei around the 'island of inversion'". United States. doi:10.1063/1.2713508.
@article{osti_21056730,
title = {Study of exotic nuclei around the 'island of inversion'},
author = {Elekes, Z. and Dombradi, Zs. and Fueloep, Zs. and Saito, A. and Baba, H. and Iwasaki, H. and Notani, M. and Ohnishi, T. K. and Ong, H. J. and Sakurai, H. and Shimoura, S. and Tamaki, M. and Aoi, N. and Imai, N. and Ishihara, M. and Kishida, T. and Kubo, T. and Michimasa, S. and Minemura, T. and Motobayashi, T.},
abstractNote = {No abstract prepared.},
doi = {10.1063/1.2713508},
journal = {AIP Conference Proceedings},
number = 1,
volume = 891,
place = {United States},
year = {Mon Feb 26 00:00:00 EST 2007},
month = {Mon Feb 26 00:00:00 EST 2007}
}
  • We report the observation of high-spin states in nuclei in the vicinity of the 'island of inversion', populated via the {sup 18}O+{sup 18}O fusion reaction at an incident beam energy of 34 MeV. The fusion reaction mechanism circumvents the limitations of other reactions used so far to populate excited states in these nuclei. The level structures of {sup 33,34}P and {sup 33}S have been investigated and their level schemes were substantially extended. The intensities and branching ratios of the {gamma} transitions were measured. The observed {gamma} coincidence intensity anisotropy and polarization asymmetry were analyzed for a consistent assignment of themore » spins and parities of the nuclear levels. The 1876-keV transition in {sup 34}P that had an ambiguous multipolarity assignment has been confirmed to be a mixed transition. Truncated (1p-1h) shell model calculations within the 'sdpf' valence space were performed. These calculations reproduce the experimental excitation energies of {sup 34}P but fail to explain the observed mixing ratio for the 1876-keV transition.« less
  • According to the argument of excitation energy systematics, new spin values are assigned to the lowest observed states of the {pi}{ital h}{sub 11/2}{circle_times}{nu}{ital h}{sub 11/2} bands for doubly odd nuclei {sup 124,126,130,132,134}La, {sup 130{endash}134}Pr, {sup 136,138}Pm, and {sup 138}Eu, and possible new spin values are discussed for doubly odd nuclei {sup 120{endash}130}Cs. Based on these new spin assignments, two systematic features of the {pi}{ital h}{sub 11/2}{circle_times}{nu}{ital h}{sub 11/2} bands are revealed. First, the low spin signature of the {pi}{ital h}{sub 11/2}{circle_times}{nu}{ital h}{sub 11/2} band is inverted for all doubly odd nuclei discussed in the present work. Second, the observed inversionmore » spin increases with increasing neutron number for Cs and La isotopes. These features are in agreement with the recent systematic calculations based on the particle-triaxial-rotor model, with the inclusion of zero-range residual interaction between unpaired proton and neutron of Semmes and Ragnarsson, performed by Tajima. {copyright} {ital 1996 The American Physical Society.}« less
  • We study the development of collectivity in the neutron-rich nuclei around N=40, where the experimental and theoretical evidence suggest a rapid shape change from the spherical to the rotational regime, in analogy to what happens at the island of inversion surrounding {sup 31}Na. Theoretical calculations are performed within the interacting shell-model framework in a large valence space, based on a {sup 48}Ca core, which encompasses the full pf shell for the protons and the 0f{sub 5/2}, 1p{sub 3/2}, 1p{sub 1/2}, 0g{sub 9/2}, and 1d{sub 5/2} orbits for the neutrons. The effective interaction is based on a G matrix obtained frommore » a realistic nucleon-nucleon potential whose monopole part is corrected empirically to produce effective single-particle energies compatible with the experimental data. We find a good agreement between the theoretical results and the available experimental data. We predict the onset of deformation at different neutron numbers for the various isotopic chains. The maximum collectivity occurs in the chromium isotopes where the large deformation regime already starts at N=38. The shell evolution responsible for the observed shape changes is discussed in detail, in parallel to the situation in the N=20 region.« less
  • The characteristics of light exotic nuclei are expected to influence the reaction mechanism in various ways. Strong direct channels are connected with the low breakup threshold for these systems. We review the problem of the influence of breakup and the other direct channels on the fusion cross section. Recent experimental results with the halo nucleus 6He and with the proton-rich 7Be nucleus are reported. From these and other measurements we try to build a consistent picture of the present understanding of the problem.
  • We investigate the {alpha}-decay half-lives of ground and isomeric states of exotic nuclei around the shell closures Z=82 and N=82 by the density-dependent cluster model (DDCM). Our calculations concentrate on four kinds of favored {alpha} transitions: (1) ground state to ground state, (2) ground state to isomeric state, (3) isomeric state to ground state, and (4) isomeric state to isomeric state. The calculated {alpha}-decay half-lives of both ground and isomeric states are found to be in good agreement with the experimental data. Useful predictions on the partial half-lives of several {alpha} emitters are made for future experiments.