Kazuyuki Ogata
A5036717125- Nuclear physics research studies
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Nuclear reactor physics and engineering
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum, superfluid, helium dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Astro and Planetary Science
- Isotope Analysis in Ecology
- Medical Imaging Techniques and Applications
- Nuclear Materials and Properties
- Neutrino Physics Research
- Mass Spectrometry Techniques and Applications
- Particle accelerators and beam dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Scientific Research and Discoveries
- Superconducting Materials and Applications
- Seismic Imaging and Inversion Techniques
Osaka University
2016-2025
Kyushu University
2008-2025
Osaka City University
2016-2023
Kyoto University
2019-2021
National Institute of Technology, Tokuyama College
2018
Université de Strasbourg
2017
Centre National de la Recherche Scientifique
2017
National Institutes for Quantum Science and Technology
2016
Japan Atomic Energy Agency
2009-2011
Advanced Science Research Center
2009-2011
Reaction cross sections (sigma(R)) for 19C, 20C and the drip-line nucleus 22C on a liquid hydrogen target have been measured at around 40A MeV by transmission method. A large enhancement of sigma(R) compared to those neighboring C isotopes was observed. Using finite-range Glauber calculation under an optical-limit approximation rms matter radius deduced be 5.4+/-0.9 fm. It does not follow systematic behavior radii in carbon with N < or = 14, suggesting neutron halo. found analysis based...
α particles in stable nuclei Decay is a common mode of radioactivity heavy elements such as uranium that entails the loss comprising two protons and neutrons. Despite more than century study, when where these form unstable alike remains an open question. Tanaka et al. bombarded series tin isotopes with high-energy detected ejected at abundance inversely correlated mass number (see Perspective by Hen). This observation, relating particle accumulation to neutron skin thickness nuclear surface,...
A kinematically complete quasi-free $(p,pn)$ experiment in inverse kinematics was performed to study the structure of Borromean nucleus $^{17}$B, which had long been considered have neutron halo. By analyzing momentum distributions and exclusive cross sections, we obtained spectroscopic factors for $1s_{1/2}$ $0d_{5/2}$ orbitals, a surprisingly small percentage 9(2)$\%$ determined $1s_{1/2}$. Our finding such component halo features reported prior experiments can be explained by deformed...
Subjecting a physical system to extreme conditions is one of the means often used obtain better understanding and deeper insight into its organization structure. In case atomic nucleus, such approach investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich exhibit most asymmetric N/Z those lying beyond limits binding, which undergo spontaneous neutron emission exist only as short-lived resonances (about 10-21 s), provide...
We propose a fully quantum-mechanical method of treating four-body nuclear breakup processes in scattering projectile consisting three constituents, by extending the continuum-discretized coupled-channels method. The three-body continuum states are discretized diagonalizing internal Hamiltonian with Gaussian basis functions. For $^6$He+$^{12}$C at 18 and 229.8 MeV, validity is tested convergence elastic cross sections respect to increasing number Effects Borromean structure $^6$He on total...
We accurately analyze the $^6$He+$^{209}$Bi scattering at 19 and 22.5 MeV near Coulomb barrier energy, using continuum-discretized coupled-channels method (CDCC) based on $n$+$n$+$^4$He+$^{209}$Bi four-body model. The three-body breakup continuum of $^6$He is discretized by diagonalizing internal Hamiltonian in a space spanned Gaussian basis functions. calculated elastic total reaction cross sections are good agreement with experimental data, while CDCC calculation di-neutron model $^6$He,...
We perform the first quantitative analysis of reaction cross sections $^{28-32}$Ne by $^{12}$C at 240 MeV/nucleon, using double-folding model (DFM) with Melbourne $g$-matrix and deformed projectile density calculated antisymmetrized molecular dynamics (AMD). To describe tail last neutron $^{31}$Ne, we adopt resonating group method (RGM) combined AMD. The theoretical prediction excellently reproduce measured no adjustable parameters. ground state properties i.e., strong deformation a halo...
The deformation of Ne isotopes in the island-of-inversion region is determined by double-folding model with Melbourne $g$-matrix and density calculated antisymmetrized molecular dynamics (AMD). reproduces, no adjustable parameter, measured reaction cross sections for scattering $^{28-32}$Ne from $^{12}$C at 240MeV/nucleon. quadrupole thus around 0.4 $^{31}$Ne a halo nuclei large deformation. We propose Woods-Saxon suitably chosen parameterization set given AMD calculation as convenient way...
In order to determine the half-life of 130 Te double β-decay, amounts and isotopic composition xenon extracted from tellurium ores, Oya gold mine in Japan, have been measured with a high-sensitivity mass spectrometer. Compared atmospheric an excess was definitely found at numbers 129, 131 xenon. The Xe is predominant, average amount three samples being (1.32 ± 0.09) × 10 -11 ccSTP/g Te. Attributing β-decay Te, estimated be (8.20 0.64) 20 years, assuming age (9.06 0.29) 7 years for ores....
In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory RIKEN. The nucleus interest produced through proton knockout from a ^{80}Zn beam 270 MeV/nucleon. level scheme up to 4.6 MeV established for first time and results are compared Monte Carlo shell-model calculations. We do not observe significant feeding excited states below 2.2 MeV, which indicates that Z=28 gap N=50 remains large. show can be described in terms valence outside ^{78}Ni core, implying...
Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a $^{54}\mathrm{Ca}$ beam striking on liquid hydrogen target at $\ensuremath{\sim}200\text{ }\text{ }\mathrm{MeV}/u$. A significantly larger section to the ${p}_{3/2}$ state compared ${f}_{5/2}$ observed in excitation of $^{53}\mathrm{Ca}$ provides direct evidence nature $N=34$ shell closure. This finding corroborates arising new closure neutron-rich calcium isotopes. The...
The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold an integrated E1 B(E1)=1.64±0.06(stat)±0.12(sys) e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft excitation, provides first firm evidence that prominent halo. Three-body...
The momentum correlation functions of $S=\ensuremath{-}2$ baryon pairs ($p{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}$ and $\mathrm{\ensuremath{\Lambda}}\mathrm{\ensuremath{\Lambda}}$) produced in high-energy $pp$ $pA$ collisions are investigated on the basis coupled-channels formalism. strong interaction is described by HAL QCD potential obtained lattice simulations near physical quark masses, while hadronic source function taken to be a static Gaussian form. effect, threshold difference,...
The cluster structure of the neutron-rich isotope ^{10}Be has been probed via (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and quasifree conditions. populated states ^{6}He residues were investigated through missing mass spectroscopy. triple differential cross section for ground-state transition was extracted angle pairs (θ_{p},θ_{α}) compared to distorted-wave impulse approximation calculations performed a microscopic framework using successively Tohsaki-Horiuchi-Schuck-Röpke...
The triple-\alpha reaction rate is re-evaluated by directly solving the three-body Schr\"odinger equation. resonant and nonresonant processes are treated on same footing using continuum-discretized coupled-channels method for scattering. Accurate description of \alpha-\alpha states significantly quenches Coulomb barrier between two-\alpha's third \alpha particle. Consequently, continuum below resonance at 92.04 keV, i.e., ground state 8Be, give markedly larger contribution low temperatures...
The nonlocality of the microscopic nucleon-nucleus optical potential is commonly localized by Brieva-Rook approximation. validity localization tested for proton+$^{90}$Zr scattering at incident energies from 65 MeV to 800 MeV. valid in wide incident-energy range.
Isotope-dependence of measured reaction cross sections in scattering $^{28-32}$Ne isotopes from $^{12}$C target at 240 MeV/nucleon is analyzed by the double-folding model with Melbourne $g$-matrix. The density projectile calculated mean-field deformed Wood-Saxon potential. deformation evaluated antisymmetrized molecular dynamics. enhances to values.
The formation of a dineutron in the nucleus $^{11}$Li is found to be localized surface region. experiment measured intrinsic momentum struck neutron via $(p,pn)$ knockout reaction at 246 MeV/nucleon. correlation angle between two neutrons is, for first time, as function momentum. A comparison with calculations reveals localization $r\sim3.6$ fm. results also support density dependence deduced from Hartree-Fock-Bogoliubov nuclear matter.
A new method of pseudostate discretization is proposed for the continuum discretized coupled channels to deal with three-body breakup processes. In method, discrete $S$-matrix elements pseudo (discretized) states are transformed into smooth ones exact projectile. As basis functions describing wave functions, we take real- and complex-range Gaussian which form in good approximation a complete set finite configuration space being important This ``approximate-completeness'' property essential...
This is a review on recent developments of the continuum discretized coupled-channels method (CDCC) and its applications to nuclear physics, cosmology astrophysics, engineering.The theoretical foundation CDCC shown, microscopic reaction theory for nucleus-nucleus scattering constructed as an underlying CDCC.CDCC then extended treat Coulomb breakup four-body breakup.We also propose new that makes applicable inclusive reactions.