Systematic study of isovector dipole mode up to A=50 KEK 研究会「原子核・ハドロン物理 : 横断研究会」 KEK, 2007 年 11 月 19 日 -21 日 稲倉恒法 中務孝 矢花一浩 ( 筑波大学 ) ( 理研 ) ( 筑波大学 )
Drip line : predicted by HFB with SkM* Phys. Rev. C68,
Nuclear Landscape terra incognita
neutron skinneutron halo radius density neutrons protons
Soft Dipole Mode AMD calc., PRC71, Egg rotation ? Collective motion unique in unstable nuclei
Systematic calculation of excited states Systematic analysis of various observables. Natures in stable region will change ? Collective motion unique in unstable nuclei Exist or not ? Which nucleus ? Microscopic description ? Motivation
deformation continuum pairing self-consistency RPA calculation for unstable nuclei Nobody made the code including all factors simultaneously.
Deformation THO+HFB+LN+PNP with SkM* & mixed pairing by M.V. Stoitsov et al., Phys. Rev. C68, prolate oblate taken from wikipedia.org.
RPA TDHF+ABC 16 O RPA vs. TDHF+ABC
Isovector dipole strengths up to Ca isotopes SkM* R box = 15 fm = 1 MeV
16 O spherical 40 Ca prolate Exp. data : Centre For Photonuclear Experiments Data
18 O prolate 24 Mg triaxial Exp. data : Centre For Photonuclear Experiments Data
Extraction of peak position and width Lorentzian Fitting RPA Lorentzian TDHF+ABC 16 O
BeNe S C Mg Ar O Si Peak position of IVGDR Cal. vs. Exp. 14 C No clear relation between evolution of peak position and deformation. Ca
Peak splitting by deformation 3D H.O. model cf. Bohr-Mottelson, text book.
Width Evolution of IVGDR short axes long axes shperical
Soft Dipole Mode? GDR pygmy J. Gibelin, Ph. D thesis. 26 Ne P. Adrich et al., PRL 95,
Pygmy resonance in 132 Sn
Particle states in pygmy resonance
26 Ne SkM* MeV K=0 K=1 Exp.
Low-lying K=1 state
Particle states in low-lying K=1 state Neutron emission
Summary Fully self-consistent deformed RPA calculation. Systematic study up to Ca isotopes. underestimate peak position of IVGDR. peak splitting by deformation. width evolution. Applied to low-lying dipole modes in 132Sn and 26Ne. soft dipole mode in 132Sn. soft dipole mode + neutron emission in 26Ne ?