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Title: Superdeformation and clustering in {sup 40}Ca studied with antisymmetrized molecular dynamics

Abstract

Deformed states in {sup 40}Ca are investigated with a method of antisymmetrized molecular dynamics. Above the spherical ground state, rotational bands arise from a normal deformation and a superdeformation as well as an oblate deformation. The calculated energy spectra and E2 transition strengths in the superdeformed band reasonably agree to the experimental data of the superdeformed band starting from the 0{sub 3}{sup +} state at 5.213 MeV. By the analysis of single-particle orbits, it is found that the superdeformed state has particle-hole nature of an 8p-8h configuration. One of new findings is parity asymmetric structure with {sup 12}C+{sup 28}Si-like clustering in the superdeformed band. We predict that {sup 12}C+{sup 28}Si molecular bands may be built above the superdeformed band due to the excitation of intercluster motion. They are considered to be higher nodal states of the superdeformed state. We also suggest negative-parity bands caused by the parity asymmetric deformation.

Authors:
;  [1]
  1. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
20771098
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 72; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.72.064322; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ASYMMETRY; CALCIUM 40; CARBON 12; E2-TRANSITIONS; ENERGY SPECTRA; EXCITATION; GROUND STATES; MEV RANGE; MOLECULAR DYNAMICS METHOD; NUCLEAR DEFORMATION; PARITY; PARTICLE-HOLE MODEL; ROTATIONAL STATES; SILICON 28; SINGLE-PARTICLE MODEL; SUPERDEFORMED NUCLEI

Citation Formats

Kanada-En'yo, Y., and Kimura, M. Superdeformation and clustering in {sup 40}Ca studied with antisymmetrized molecular dynamics. United States: N. p., 2005. Web. doi:10.1103/PhysRevC.72.064322.
Kanada-En'yo, Y., & Kimura, M. Superdeformation and clustering in {sup 40}Ca studied with antisymmetrized molecular dynamics. United States. doi:10.1103/PhysRevC.72.064322.
Kanada-En'yo, Y., and Kimura, M. Thu . "Superdeformation and clustering in {sup 40}Ca studied with antisymmetrized molecular dynamics". United States. doi:10.1103/PhysRevC.72.064322.
@article{osti_20771098,
title = {Superdeformation and clustering in {sup 40}Ca studied with antisymmetrized molecular dynamics},
author = {Kanada-En'yo, Y. and Kimura, M.},
abstractNote = {Deformed states in {sup 40}Ca are investigated with a method of antisymmetrized molecular dynamics. Above the spherical ground state, rotational bands arise from a normal deformation and a superdeformation as well as an oblate deformation. The calculated energy spectra and E2 transition strengths in the superdeformed band reasonably agree to the experimental data of the superdeformed band starting from the 0{sub 3}{sup +} state at 5.213 MeV. By the analysis of single-particle orbits, it is found that the superdeformed state has particle-hole nature of an 8p-8h configuration. One of new findings is parity asymmetric structure with {sup 12}C+{sup 28}Si-like clustering in the superdeformed band. We predict that {sup 12}C+{sup 28}Si molecular bands may be built above the superdeformed band due to the excitation of intercluster motion. They are considered to be higher nodal states of the superdeformed state. We also suggest negative-parity bands caused by the parity asymmetric deformation.},
doi = {10.1103/PhysRevC.72.064322},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 72,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}
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  • The low-lying states of {sub {Lambda}}{sup 21}Ne are studied with antisymmetrized molecular dynamics for hypernuclei. We have obtained ten rotational bands where the number of bands are increased compared to {sup 20}Ne by adding a {Lambda} hyperon. Among them, we focus on the K{sup {pi}=}0{sub 1}{sup +} x {Lambda}{sub s} and K{sup {pi}=}0{sub 1}{sup -} x {Lambda}{sub s} bands. The former has a shell-model-like structure that has {Lambda} in an s wave coupled to the ground band of {sup 20}Ne. The latter is a cluster state that has a {alpha}+{sub {Lambda}}{sup 17}O dicluster structure. The difference between their structures leadsmore » to the binding energy of {Lambda} particle B{sub {Lambda}} and reduction of the E2 transition probabilities B(E2).« less
  • A new microscopic simulation method of heavy-ion collisions is formulated by incorporating the two-nucleon collision process into the antisymmetrized version of molecular dynamics. This method can describe quantum-mechanical features such as shell effects. The fragment mass distribution of the {sup 12}C+{sup 12}C reaction at 28.7 MeV/nucleon is shown to be reproduced very well by this new method combined with the treatment of statistical cascade decays of excited fragments, which verifies the usefulness of the new method.
  • The intermediate energy ({ital p},{ital p}{prime}{ital x}) reaction is studied with antisymmetrized molecular dynamics (AMD) in the cases of {sup 58}Ni target with {ital E}{sub {ital p}}=120 MeV and {sup 12}C target with {ital E}{sub {ital p}}=200 and 90 MeV. Angular distributions for various {ital E}{sub {ital p}{prime}} energies are shown to be reproduced well without any adjustable parameter, which shows the reliability and usefulness of AMD in describing light-ion reactions. Detailed analyses of the calculations are made in the case of {sup 58}Ni target and the following results are obtained: Two-step contributions are found to be dominant in somemore » large angle region and to be indispensable for the reproduction of data. Furthermore, the reproduction of data in the large angle region {theta}{approx_gt}120{degree} for {ital E}{sub {ital p}{prime}}=100 MeV is shown to be due to three-step contributions. Angular distributions for {ital E}{sub {ital p}{prime}}{approx_gt}40 MeV are found to be insensitive to the choice of different in-medium nucleon-nucleon cross sections {sigma}{sub {ital N}{ital N}} and the reason for this insensitivity is discussed in detail. On the other hand, the total reaction cross section and the cross section of evaporated protons are found to be sensitive to {sigma}{sub {ital N}{ital N}}. In the course of the analyses of the calculations, comparison is made with the distorted wave approach.« less