335 research outputs found
Structure of Light Unstable Nuclei Studied with Antisymmetrized Molecular Dynamics
Structures of light unstable nuclei, Li, Be, B, and C isotopes are
systematically studied with a microscopic method of antisymmetrized molecular
dynamics. The theoretical method is found to be very useful to study ground and
excited states of various nuclei covering unstable nuclei. The calculations
succeed to reproduce many experimental data for nuclear structures; energies,
radii, magnetic dipole moments, electric quadrupole moments, transition
strength. In the theoretical results it is found that various exotic phenomena
in unstable nuclei such as molecular-like structures, neutron skin, and large
deformations may appear in unstabel nuclei. We investigate the structure change
with the increase of neutron number and with the increase of the excitation
energies, and find the drastic changes between shell-model-like structures and
clustering structures. The mechanism of clustering developments in unstable
nuclei are discussed.Comment: 73 pages, Revtex, 42 postscript figures (using epsf.sty). to be
published in Suppl. Prog. Theor. Phy
Cluster formations in deformed states for Si and S
We study cluster formation in strongly deformed states for Si and
S using a macroscopic-microscopic model. The study is based on
calculated total-energy surfaces, which are the sums of deformation-dependent
macroscopic-microscopic potential-energy surfaces and rotational-energy
contributions. We analyze the angular-momentum-dependent total-energy surfaces
and identify the normal- and super-deformed states in Si and S,
respectively. We show that at sufficiently high angular momenta strongly
deformed minima appear. The corresponding microscopic density distributions
show cluster structure that closely resemble the O+C and
O+O configurations. At still higher deformations, beyond the
minima, valleys develop in the calculated surfaces. These valleys lead to mass
divisions that correspond to the target-projectile configurations for which
molecular resonance states have been observed. We discuss the relation between
the one-body deformed minima and the two-body molecular-resonance states.Comment: 6 pages, 7 figure
Structures and Transitions in Light Unstable Nuclei
We study the structures of the unstable Be isotopes with the theoretical
method of antisymmetrized molecular dynamics. It is found that various
structures of the excited states appear in the low-energy region of
neutron-rich Be nuclei. Focusing on the 2 clustering, we analyze the
intrinsic structures with the help of the experimental data of Gamow-Teller
transitions.Comment: 8 pages and 4 figure
Cluster structure in stable and unstable nuclei
Cluster structure in stable and unstable nuclei has been studied. We report
recent developments of theoretical studies on cluster aspect, which is
essential for structure study of light unstable nuclei. We discuss negative
parity bands in even-even Be and Ne isotopes and show the importance of cluster
aspect. Three-body cluster structure and cluster crystallization are also
introduced. It was found that the coexistence of cluster and mean-field aspect
brings a variety of structures to unstable nuclei.Comment: 6 pages, 3 figures, submitted to Euro. Phys. J.
Structure of excited states of Be-11 studied with Antisymmetrized Molecular Dynamics
The structures of the ground and excited states of Be-11 were studied with a
microscopic method of antisymmetrized molecular dynamics. The theoretical
results reproduce the abnormal parity of the ground state and predict various
kinds of excited states. We suggest a new negative-parity band with a
well-developed clustering structure which reaches high-spin states. Focusing on
a clustering structure, we investigated structure of the ground and
excited states. We point out that molecular orbits play important roles for the
intruder ground state and the low-lying states. The features of
the breaking of clusters were also studied with the help of data for
Gamow-Teller transitions.Comment: 24 pages, 7 figures, to be submitted to Phys.Rev.
Structure of Excited States of 10Be studied with Antisymmetrized Molecular Dynamics
We study structure of excited states of 10Be with the method of variation
after spin parity projection in the framework of antisymmetrized molecular
dynamics. Present calculations describe many excited states and reproduce the
experimental data of E2 and E1 transitions and the new data of the
transition strength successfully. We make systematic discussions on the
molecule-like structures of light unstable nuclei and the important role of the
valence neutrons based on the results obtained with the framework which is free
from such model assumptions as the existence of inert cores and clusters.Comment: 15 pages, RevTex, seven postscript figures (using epsf.sty
New effective nuclear forces with a finite-range three-body term and their application to AMD+GCM calculations
We propose new effective inter-nucleon forces with a finite-range three-body
operator. The proposed forces are suitable for describing the nuclear structure
properties over a wide mass number region, including the saturation point of
nuclear matter. The forces are applied to microscopic calculations of
() nuclei and O isotopes with a method of antisymmetrized molecular
dynamics. We present the characteristics of the forces and discuss the
importance of the finite-range three-body term.Comment: 15 pages, 11 figures, submitted to Phys.Rev.
Clustering in stable and unstable nuclei in -shell and -shell regions
According to microscopic calculations with antisymmetrized molecular
dynamics, we studied cluster features in stable and unstable nuclei. A variety
of structure was found in stable and unstable nuclei in the -shell and
-shell regions. The structure of excited states of Be was
investigated, while in -shell nuclei we focused on molecular states and
deformed states. The deformed states in Si and Ca were discussed
in connection with the high-lying molecular states. Appealing molecular states
in Ar and Mg were suggested. The results signified that both
clustering of nucleons and mean-field formation are essential features in
-shell nuclei as well as -shell nuclei.Comment: 5 pages, 2 figs, proceedings of the 8th International conference on
Clustering Aspects of Nuclear Structure and Dynamics, Nov. 2003, Nara, Japan,
to be published in Nucl.Phys.
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