A5088203613- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Quantum chaos and dynamical systems
- Advanced NMR Techniques and Applications
- Atomic and Molecular Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Astronomical and nuclear sciences
- Pulsars and Gravitational Waves Research
- Advanced Chemical Physics Studies
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Nuclear Physics and Applications
- Neutrino Physics Research
- Scientific Research and Discoveries
- Physics of Superconductivity and Magnetism
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- High-Energy Particle Collisions Research
- Quantum many-body systems
- Chaos control and synchronization
- Geophysics and Sensor Technology
- Gamma-ray bursts and supernovae
- Theoretical and Computational Physics
- Particle accelerators and beam dynamics
Saitama University
2015-2024
Nihon University
2018
High Energy Accelerator Research Organization
2017
Urawa University
1994-2013
Seikei University
2003
The University of Tokyo
1984-1991
University of Oxford
1988-1990
RIKEN
1986
Excited states of ${}^{76}$Ge have been populated in above-barrier Coulomb excitation and inelastic scattering a 530-MeV beam on ${}^{238}$U target studied using in-beam $\ensuremath{\gamma}$-ray spectroscopy with the Gammasphere array. The $\ensuremath{\gamma}$ band was extended considerably one new identified. Comparisons collective- shell-model calculations suggest that may be rare example nucleus exhibiting rigid triaxial deformation low-lying states.
The intrinsic state of the Nilsson model is analyzed in terms nucleon pairs coupled to spins ${0}^{+}$, ${2}^{+}$, ${4}^{+}$, ${6}^{+}$,.... It shown that ${0}^{+}$ and ${2}^{+}$ dominate Cooper pair which constitutes with large quadrupole deformation.
The formalism for the nucleon-pair approximation of shell model (NPSM) is greatly simplified by applying Wick theorem coupled cluster in a more sagacious way. Using new coupling scheme basis, not only unifies analytic expressions Hamiltonian matrix elements even and odd nuclei (odd-even or odd-odd), but importantly reduces computing time drastically, which crucial NPSM calculations to be realizable.
A multinucleon transfer reaction between a thin self-supporting Pt 78198 target and an 850MeV Xe 54136 beam has been used to populate study the structure of N=80 isotone Ba 56136. Making use time-correlated γ-ray spectroscopy, evidence for Iπ=(10+) isomeric state found with measured half-life 91±2ns. Prompt-delayed correlations have also enabled tentative measurement near-yrast states which lie above isomer. Shell-model calculations suggest that isomer can be assigned predominantly as...
Systematic studies are carried out for Xe, Ba, Ce, and Nd isotopes within the framework of pair-truncated shell model where collective nucleon pairs with angular momenta zero $(S)$ two $(D)$ assumed to be building blocks even-even nuclei. An additional unpaired is added core a description odd-mass It found that energy spectra low-lying states nicely reproduced along intraband interband $E2$ transitions, which simulate typical features O(6) limit interacting boson model.
The $\mathrm{sdg}$ interacting-boson model is applied to $^{168}\mathrm{Er}$. Energy levels and $E2$ transitions are calculated. This shown solve the problem of anharmonicity regarding excitation energy first ${K}^{\ensuremath{\pi}}={4}^{+}$ band relative that ${K}^{\ensuremath{\pi}}={2}^{+}$ one. level scheme including ${K}^{\ensuremath{\pi}}={3}^{+}$ well reproduced calculated $B(E2)$'s consistent with experimental data.
Low-lying states for even-even, odd-mass, and doubly odd nuclei in the mass $A~130$ region are systematically investigated using a pair-truncated shell model. In this model collective nucleon pairs with angular momenta zero two basic ingredients even-even nuclei. Additional unpaired nucleons added to core description of odd-mass The effective interactions consist single-particle energies monopole quadrupole pairing plus quadrupole-quadrupole interactions, whose strengths assumed be linearly...
Shell-model calculations are performed for even-even, odd-mass, and doubly-odd nuclei of Sn, Sb, Te, I, Xe, Cs, Ba isotopes around mass 130 using the single-particle space made up valence nucleons occupying $0{g}_{7/2},\phantom{\rule{0.16em}{0ex}}1{d}_{5/2},\phantom{\rule{0.16em}{0ex}}2{s}_{1/2},\phantom{\rule{0.16em}{0ex}}0{h}_{11/2}$, $1{d}_{3/2}$ orbitals. The calculated energies electromagnetic transitions compared with experimental data. In addition, several typical isomers in this...
The nucleon pair shell model calculation is performed in terms of the SD collective pairs which are obtained a suitable way to obtain maximum collectivity. method applied even-even Sn, Te, Xe, Ba, and Ce isotopes near $A=130$ region employing (monopole quadrupole) pairing plus quadrupole-quadrupole-type interaction with very few parameters. structure energy levels for quasi-\ensuremath{\gamma} band as well ground reproduced each nucleus. Other properties such $E2$ transition rates binding...
The validity of the essential ingredients microscopic formulation interacting boson model: (i) truncation shell-model or fermion space and (ii) procedures for mapping truncated on to space, is tested over various (spherical, deformed transitional) regions both in simplistic single j-shell, identical sys tems more realistic multi proton-neutron systems depending feasibility such calculations. In situations where fail reproduce exact results, it demonstrated that renormalization higher order...
Quantum-number projection is applied to generate exact eigenstates of angular momentum or particle numbers from the self-consistent solution angular-momentum- and particle-number-constrained Hartree-Fock-Bogoliubov (CHFB) equation. Calculations are based on symmetry-conserving microscopic Hamiltonian large single-particle space spanned by spherical Nilsson bases covering about 1.5 major shells for both protons neutrons in case yrast bands ${}^{158,164,168}\mathrm{Er}$ almost three...
Backbending phenomena and low-lying collective states in the nucleus ${}^{132}\mathrm{Ba}$ are studied terms of a pair-truncated shell model with monopole quadrupole pairing plus quadrupole-quadrupole interaction. The reproduces well experimental energy levels, transition rates, g factors for both those around backbending region. pair truncation shell-model space yields remarkable results states, alignment two ${0h}_{11/2}$ neutrons plays decisive role describing backbending.
Full-fledged shell-model calculations have been performed for neutron-rich Se, As, Ge, and Ga isotopes using a valence space made up from nucleons occupying the ${g}_{9/2},{p}_{1/2},{p}_{3/2}$, ${f}_{5/2}$ orbitals. The calculated energies electromagnetic transitions are compared with experimental data which is available on these nuclei. Pair-truncated shell model also carried out to investigate structure of high-spin states, particular focus effect alignment neutrons in ${g}_{9/2}$ orbital.
Large-scale shell-model calculations are performed for even-even, odd-mass, and doubly odd nuclei of Pb, Bi, Po, At, Rn, Fr isotopes in the neutron deficit region $(Z\ensuremath{\ge}82,N\ensuremath{\le}126)$ assuming $^{208}\mathrm{Pb}$ as a magic core. All six single-particle orbitals between numbers 82 126, namely, $0{h}_{9/2},1{f}_{7/2},0{i}_{13/2},2{p}_{3/2},1{f}_{5/2}$, $2{p}_{1/2}$, considered. For phenomenological effective two-body interaction, one set monopole pairing...
The validity of the SD-pair truncation shell model is tested in a single j and many shells within framework nucleon pair model. It found that good approximation single-j case when Hamiltonian consists (monopole quadrupole) pairing plus quadrupole-quadrupole-type interaction. deteriorates if quadrupole-quadrupole interaction artificially large compared with monopole For multi-j shells, schematic calculations degenerate sd, pf, sdg are performed for extreme pure There difference between...
The nuclear structure of the $\ensuremath{\Delta}I=1$ doublet bands in doubly-odd nuclei $^{130}\mathrm{Cs}$, $^{132}\mathrm{Cs}$, $^{132}\mathrm{La}$, and $^{134}\mathrm{La}$ is studied terms a pair-truncated shell model, which collective nucleon pairs with angular momenta zero two are its basic ingredients. effective interactions consist single-particle energies monopole quadrupole pairing plus quadrupole-quadrupole interactions, whose strengths determined so as to describe level schemes...
The electric dipole moment of a neutral atom is mainly induced by the nuclear Schiff moment. wave functions beyond mean-field theories are calculated in terms shell model, which contains two-body interactions violating parity and time-reversal invariance. Using thus obtained, moments for lowest $1/{2}^{+}$ states Xe isotopes calculated. upper limit ${}^{129}$Xe estimated using its
The electric dipole moments for the lowest $1/{2}^{+}$ states of Xe and Ba isotopes are calculated in terms nuclear shell model, which includes two-body nucleon interactions violating parity time-reversal invariance. Using wave functions thus obtained, arising from intrinsic also asymmetric charge distribution calculated. upper limits estimated.
The sdg interacting-boson model is presented in the SU(3) tensor formalism. interactions are decomposed according to their character. existence of SU(3)-seniority preserving operator found be important. applied $^{168}\mathrm{Er}$. Energy levels and electromagnetic transitions calculated. This shown solve problem anharmonicity regarding excitation energy first ${K}^{\ensuremath{\pi}}$${=4}^{+}$ band relative that ${K}^{\ensuremath{\pi}}$${=2}^{+}$ one. E4 calculated give different...
Nuclear electric dipole moments (EDMs) and Schiff for the lowest 1/2+ states around mass 130 are calculated in terms of nuclear shell model. We estimate upper limits EDMs, which may be directly measured through ionic atoms. The EDM each nucleus is slightly quenched from its single-particle due to many-body effects. also limit neutral 129Xe atom using moment.