2011/04/20 by Yoshiko Kanada-En’yo, Yoshiko Kanada-En'yo, Yoshimasa Hidaka
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Atomic physics #Center (category theory) #Chemistry #Cluster (spacecraft) #Crystallography #Geometry #High-pressure geophysics and materials #Oblate spheroid #Parity (physics) #Pentagon #Physics #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #nucl-th
paper · pdf · doi:10.1103/physrevc.84.014313
published as Phys.Rev.C84:014313,2011 · 23 pages, 8 figures
arxiv created 2011/04/20 · openalex publication_date 2011/07/14 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Pentagon and triangle shapes in 28Si and 12C are discussed in relation to nuclear density waves. In the antisymmetrized molecular dynamics calculations, the K^\ensuremathπ=5^\ensuremath- band in 28Si and the K^\ensuremathπ=3^\ensuremath- band in 12C are described by the pentagon and triangle shapes, respectively. These negative-parity bands can be interpreted as the parity partners of the K^\ensuremathπ=0+ ground bands and they are constructed from the parity-asymmetric-intrinsic states. The pentagon and the triangle shapes originate in 7\ensuremathα- and 3\ensuremathα-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 \ensuremathα-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\ensuremath≠N nuclei.