# {alpha}-cluster structure and density waves in oblate nuclei

## Abstract

Pentagon and triangle shapes in {sup 28}Si and {sup 12}C are discussed in relation to nuclear density waves. In the antisymmetrized molecular dynamics calculations, the K{sup {pi}=}5{sup -} band in {sup 28}Si and the K{sup {pi}=}3{sup -} band in {sup 12}C are described by the pentagon and triangle shapes, respectively. These negative-parity bands can be interpreted as the parity partners of the K{sup {pi}=}0{sup +} ground bands and they are constructed from the parity-asymmetric-intrinsic states. The pentagon and the triangle shapes originate in 7{alpha}- and 3{alpha}-cluster structures, respectively. In a mean-field picture, they are described also by the static one-dimensional density waves at the edge of the oblate states. In analyses with ideal {alpha}-cluster models using Brink-Bloch cluster wave functions and that with a simplified model, we show that the static edge density waves for the pentagon and triangle shapes can be understood by spontaneous breaking of axial symmetry, i.e., the instability of the oblate states with respect to the edge density waves. The density wave is enhanced in the Z=N nuclei due to the proton-neutron coherent density waves, while it is suppressed in Z{ne}N nuclei.

- Authors:

- Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
- (Japan)

- Publication Date:

- OSTI Identifier:
- 21596559

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review. C, Nuclear Physics

- Additional Journal Information:
- Journal Volume: 84; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevC.84.014313; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2813

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ASYMMETRY; AXIAL SYMMETRY; CARBON 12; CLUSTER MODEL; DENSITY; INSTABILITY; KAONS MINUS; MEAN-FIELD THEORY; MOLECULAR DYNAMICS METHOD; NEUTRONS; NUCLEAR MATTER; PROTONS; SILICON 28; WAVE FUNCTIONS; BARYONS; BOSONS; CALCULATION METHODS; CARBON ISOTOPES; ELEMENTARY PARTICLES; EVEN-EVEN NUCLEI; FERMIONS; FUNCTIONS; HADRONS; ISOTOPES; KAONS; LIGHT NUCLEI; MATHEMATICAL MODELS; MATTER; MESONS; NUCLEAR MODELS; NUCLEI; NUCLEONS; PHYSICAL PROPERTIES; PSEUDOSCALAR MESONS; SILICON ISOTOPES; STABLE ISOTOPES; STRANGE MESONS; STRANGE PARTICLES; SYMMETRY

### Citation Formats

```
Kanada-En'yo, Yoshiko, Hidaka, Yoshimasa, and Mathematical Physics Laboratory, RIKEN Nishina Center, Saitama 351-0198.
```*{alpha}-cluster structure and density waves in oblate nuclei*. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVC.84.014313.

```
Kanada-En'yo, Yoshiko, Hidaka, Yoshimasa, & Mathematical Physics Laboratory, RIKEN Nishina Center, Saitama 351-0198.
```*{alpha}-cluster structure and density waves in oblate nuclei*. United States. doi:10.1103/PHYSREVC.84.014313.

```
Kanada-En'yo, Yoshiko, Hidaka, Yoshimasa, and Mathematical Physics Laboratory, RIKEN Nishina Center, Saitama 351-0198. Fri .
"{alpha}-cluster structure and density waves in oblate nuclei". United States. doi:10.1103/PHYSREVC.84.014313.
```

```
@article{osti_21596559,
```

title = {{alpha}-cluster structure and density waves in oblate nuclei},

author = {Kanada-En'yo, Yoshiko and Hidaka, Yoshimasa and Mathematical Physics Laboratory, RIKEN Nishina Center, Saitama 351-0198},

abstractNote = {Pentagon and triangle shapes in {sup 28}Si and {sup 12}C are discussed in relation to nuclear density waves. In the antisymmetrized molecular dynamics calculations, the K{sup {pi}=}5{sup -} band in {sup 28}Si and the K{sup {pi}=}3{sup -} band in {sup 12}C are described by the pentagon and triangle shapes, respectively. These negative-parity bands can be interpreted as the parity partners of the K{sup {pi}=}0{sup +} ground bands and they are constructed from the parity-asymmetric-intrinsic states. The pentagon and the triangle shapes originate in 7{alpha}- and 3{alpha}-cluster structures, respectively. In a mean-field picture, they are described also by the static one-dimensional density waves at the edge of the oblate states. In analyses with ideal {alpha}-cluster models using Brink-Bloch cluster wave functions and that with a simplified model, we show that the static edge density waves for the pentagon and triangle shapes can be understood by spontaneous breaking of axial symmetry, i.e., the instability of the oblate states with respect to the edge density waves. The density wave is enhanced in the Z=N nuclei due to the proton-neutron coherent density waves, while it is suppressed in Z{ne}N nuclei.},

doi = {10.1103/PHYSREVC.84.014313},

journal = {Physical Review. C, Nuclear Physics},

issn = {0556-2813},

number = 1,

volume = 84,

place = {United States},

year = {2011},

month = {7}

}