Prof. Ikuko Hamamoto

Division of Mathematical Physics, LTH, University of Lund, Lund, Sweden, and The Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark, and Riken Nishina-Center, Wako, Saitama, Japan

Curator and author

• Shape deformations in atomic nuclei
• (2012) Ikuko Hamamoto, Ben Mottelson

 

Curriculum Vitae

Figure 1: Pr.Ikuko Hamamoto

• Born : Nov.11, 1936, in Shanghai, China
• Sex : female
• Nationality : Japanese
• e-mail : IKUKO at MATFYS.LTH.SE or IKUKO at RIBF.RIKEN.JP (for Japanese)

Main points of scientific career

• March, 1959 : B.S., Department of Physics, University of Tokyo, Japan.
• March, 1961 : M.S., Department of Physics, University of Tokyo, Japan.
• March, 1964 : PhD, physics at University of Tokyo, Japan.
• April, 1964 : research associate, University of Tokyo, Japan.
• April, 1973 : assistant professor at NORDITA (Nordic Institute for Theoretical Atomic Physics),Copenhagen, Denmark.
• April, 1982 : chair professor of Mathematical Physics, LTH, University of Lund, Sweden.
• Nov., 2001 : Professor emeritus of the University of Lund, Sweden.
• 2002 - 2012 : adjoint professor of the Niels Bohr Institute, University of Copenhagen, Denmark.
• Dec., 2011 - present : senior visiting scientist, RIKEN, Japan

Nominations/awards

• Foreign member of the Royal Danish Academy of Sciences and Letters (Det Kongelige Danske Videnskabernes Selskab), since 1998.
• Member of “Kungliga Fysiografiska Saellskapet i Lund, Sweden - Akademi for Naturvetenskap, Medicin och Teknik”, since 1984.
• Outstanding referee nominated by American Physical Society in 2008.

Scientific interests

I have been interested in the understanding and interpretation of a variety of different nuclear phenomena, having intimate contact with experimental developments in the field. Naming a few in detail; (a) I made contributions to the development of the modern version of particle-vibration coupling as a central concept for the interweaving of single-particle and collective degrees of freedom. My contribution was extended to the effective interactions between single-particle and collective modes, the decay patterns of vibrational multiplets, the one-particle transfer excitation of such multiplets, polarization effects, and transition densities for exciting collective modes. Among others, the analysis of the decay of octupole-septuplet members in ²⁰⁹Bi is one of the most beautiful examples in which E1 polarization charge was quantitatively pinned down. (b) In the properties of deformed nuclei, especially those associated with rotational motion, I may mention my critical analysis and understanding of the physics in the band-crossing phenomena related to the cranking model, in addition to the relation of electromagnetic transitions in rotating nuclei to the nuclear shape. (c) In the search for triaxial nuclear shape I made basic predictions as to the features of electromagnetic transitions characterizing triaxial shape. I suggested and pinned down that the experimental finding by G.B.Hagemann et al. in 2001 is the discovery of wobbling mode. Then, my prediction of the presence and properties of the band with two wobbling phonons in ¹⁶³Lu urged the experimentalists to look for it. The band was subsequently found. (d) Together with G.Bertsch in 1982 I pointed out that the tensor force could shift an appreciable amount of Gamow-Teller strength to the energy much higher than that of the Giant Resonance (GR), and thereby explained the considerable amount of missing strength in observed GT GR. The higher-lying GT strength was indeed observed at the end of the nineties. (e) Together with Mottelson, Xie and Zhang in 1991 I studied the shell structure and octupole instability in Fermion systems. The study was originally intended for atomic cluster systems, but the beautiful result based on the group theory together with numerical calculations throughly worked out invited later some nuclear theorists to apply the idea also to nuclei, especially searching for the Y32 (tetrahedron) deformation. (f)In the physics of drip line nuclei I have studied (1993-present) the change of shell-structure, polarization effects, giant resonances, one-particle resonant levels etc. The study will contribute to the field exploited by radioactive-ion-beams, the facilities of which are either under operation or currently being constructed.

Some representative publications

• I. Hamamoto, Particle spectra and particle-vibration coupling in the Pb region, Physics Reports, 10 (1974) 63-105.
• I. Hamamoto, Band-crossing in the cranking model, Nucl. Phys. A271 (1976) 15.
• G.F. Bertsch and I. Hamamoto, Gamow-Teller strength at high excitations, Phys. Rev. 26C (1982) 1323.
• I. Hamamoto and B. Mottelson, Transition rates for triaxial rotor plus a single quasiparticle, Phys. Lett. 132B (1983) 7.
• I. Hamamoto, Rotational motion of triaxial-shape in unfavored-signature states of odd-A nuclei, Phys. Lett., 193B (1987) 399.
• I. Hamamoto, B. Mottelson, H. Xie and X.Z. Zhang, Shell-structure and octupole instability in Fermion systems, Zeit. Phys. D21 (1991) 163.
• I. Hamamoto and B. Mottelson, Superdeformed rotational bands in the presence of Y44 deformations, Phys. Lett. 333B (1994) 294.
• S.W. Odegaard, G.B. Hagemann, I. Hamamoto et al., First evidence for the wobbling mode in nuclei, Phys. Rev. Lett. 86 (2001) 5866.
• T. Koike, K. Starosta and I. Hamamoto, Chiral bands and the selection-rule for electromagnetic transitions in the chiral geometry, Phys. Rev. Lett. 93 (2004) 172502.
• I. Hamamoto, One-particle resonant levels in deformed potential, Phys. Rev. C72 (2005)024301.
• I. Hamamoto, Nilsson diagrams for light neutron-rich nuclei with weakly-bound neutrons, Phys. Rev. C76 (2007) 054319.