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T Mizusaki

Publications and source records attributed to T Mizusaki.

17 recordsLinked to original sources

Magic numbers in exotic nuclei and spin-isospin properties of the NN interaction.

The magic numbers in exotic nuclei are discussed, and their novel origin is shown to be the spin-isospin dependent part of the nucleon-nucleon interaction in nuclei. The importance and robustness of this mechanism is shown in terms of meson exchange, G-matrix, and QCD theories. In neutron-rich exotic nuclei, magic numbers such as N = 8, 20, etc. can disappear, while N = 6, 16, etc. arise, affecting the structure of the lightest exotic nuclei to nucleosynthesis of heavy elements.

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Transition from spherical to deformed shapes of nuclei in the Monte Carlo shell model.

The transition from spherical to deformed shapes is studied in terms of large-scale shell-model calculations for Ba isotopes as a function of valence nucleon number with fixed single-particle space and Hamiltonian. A new version of the Monte Carlo shell model is introduced so as to incorporate pairing correlations efficiently, by utilizing condensed pair bases. The energy levels and electromagnetic matrix elements are described in agreement with experiments throughout the transitional region. The orbital M1 sum rule is calculated as a measure of the deformation evolution, and the Q-phonon picture is shown to be reasonable from spherical to deformed nuclei.

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Sound velocity measurements of nuclear-ordered solid 3He along the melting curve.

We have measured the temperature dependence of the 10.98 MHz longitudinal sound velocity of solid 3He in the nuclear-ordered U2D2 phase and in the paramagnetic phase along the melting curve. The temperature dependence of the sound was attributed to the contributions from the nuclear spin system and the molar volume change along the melting curve. The sound velocity increased with temperature as T4 in the U2D2 phase and the sound anisotropy due to the exchange interaction was found to be about 10% among single-domain crystals investigated. The average value of the Gruneisen constant of the spin wave velocity in the ordered phase was gamma(c) = 16 and is compared to the calculated value of the multiple-exchange model.

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Excitation spectrum and effective mass of the even-fraction quantum hall liquid

To probe the nature of the even-fraction quantum Hall system, we have investigated the low-lying excitation spectrum by exact diagonalization for finite systems. We have found (i) a striking one-to-one correspondence (i.e., a shell structure) between the spectrum and those for free (composite) fermions, (ii) a surprisingly straight scaling plot for the excitation energy that gives a zero gap (metal) in the thermodynamic limit, (iii) the effective mass evaluated from the scaling becoming heavier for nu = 1/2,1/4,1/6, but (iv) some deviations from the single-mode or the Hartree-Fock composite fermion approximation.

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