H. Akimune
A5001640659- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Particle physics theoretical and experimental studies
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Nuclear reactor physics and engineering
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Rare-earth and actinide compounds
- Medical Imaging Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Dark Matter and Cosmic Phenomena
- Advanced X-ray Imaging Techniques
- Muon and positron interactions and applications
Konan University
2016-2025
University of Notre Dame
1994-2016
National Institutes for Quantum Science and Technology
2016
Osaka University
1996-2011
Japan Atomic Energy Agency
1999-2011
Japan Radioisotope Association
2011
Tohoku University
2011
Tokyo Institute of Technology
2011
University of Groningen
2011
National Institute of Advanced Industrial Science and Technology
2009-2011
The gamman-->K(+)K(-)n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed 1.54+/-0.01 GeV/c(2) with a width smaller than 25 MeV/c(2) Gaussian significance of 4.6sigma. strangeness quantum number (S) the is +1. It can be interpreted as molecular meson-baryon or alternatively an exotic five-quark state (uuddsmacr;) that decays into neutron. consistent lowest member antidecuplet baryons predicted chiral soliton model.
The strength distributions of the giant monopole resonance (GMR) have been measured in even-A Sn isotopes (A=112-124) with inelastic scattering 400-MeV alpha particles angular range 0 degrees -8.5 . We find that experimentally observed GMR energies are lower than values predicted by theoretical calculations reproduce 208Pb and 90Zr very well. From data, a value Ktau = -550 +/- 100 MeV is obtained for asymmetry term nuclear incompressibility.
Inelastic scattering from ${}^{12}$C has been measured at extremely forward angles including 0 ${}^{\ensuremath{\circ}}$ using 386 MeV $\ensuremath{\alpha}$ particles to study the $\ensuremath{\alpha}$-cluster states around ${E}_{x}$ $\ensuremath{\sim}$ 10 MeV, especially 2${}^{+}$ state predicted by model. We have analyzed ($\ensuremath{\alpha}$,${\ensuremath{\alpha}}^{\ensuremath{'}}$) cross-section data both peak-fitting and multipole decomposition techniques. A ${E}_{x}=$ 9.84...
Differential cross sections and photon beam asymmetries for the gamma p rightarrow K+ Lambda Sigma0 reactions have been measured in energy range from 1.5 GeV to 2.4 angular Theta_{cm} = 0 60 of scattering angle center mass system at SPring-8/LEPS facility. The both found be positive increase with energy. differential agree data by CLAS collaboration cosTheta_{cm}<0.9 within experimental uncertainties, but discrepancy SAPHIR K+Lambda reaction is large cosTheta_{cm}>0.9. In reaction,...
We have investigated the isoscalar giant resonances in Sn isotopes using inelastic scattering of 386-MeV alpha-particles at extremely forward angles, including 0deg. obtained completely "background-free inelastic-scattering spectra for over angular range 0deg--9deg and up to an excitation energy 31.5 MeV. The strength distributions various multipoles were extracted by a multipole decomposition analysis based on expected respective multipoles. find that centroid energies monopole resonance...
The cross sections of the isovector spin-dipole resonances (SDR) in Sb isotopes excited by ${(}^{3}\mathrm{He},t)$ charge-exchange reaction at 450 MeV for $0\ifmmode^\circ\else\textdegree\fi{}\ensuremath{\le}{\ensuremath{\theta}}_{t}\ensuremath{\le}1.15\ifmmode^\circ\else\textdegree\fi{}$ have been measured. results are compared with predicted sum-rule strengths related to difference neutron and proton root-mean-square radii. Within model used, radii differences (neutron-skin thicknesses)...
The photo-production of ϕ mesons from Li, C, Al, and Cu at forward angles has been measured Eγ=1.5–2.4GeV. number events for incoherent is found to have a target mass dependence A0.72±0.07 in the kinematical region |t|⩽0.6GeV2/c2. total cross section ϕ–nucleon interaction, σϕN, estimated as 35−11+17mb using A-dependence yield Glauber-type multiple scattering theory. This value much larger than σϕN free space, suggesting that properties might change nuclear medium.
The cluster structures of the excited states in $^{11}$B are studied by analyzing isoscalar monopole and quadrupole strengths $^{11}$B($d$,$d'$) reaction at $E_d=200$ MeV. excitation compared with predictions shell-model antisymmetrized molecular-dynamics (AMD) calculations. It is found that large strength for $3/2^-_3$ state $E_x=8.56$ MeV well described AMD calculation an evidence a developed $2\alpha+t$ structure.
The γd→K+K−pn reaction has been studied to search for the evidence of Θ+ by detecting K+K− pairs at forward angles. Fermi-motion-corrected nK+ invariant mass distribution shows a narrow peak 1.524±0.002+0.003 GeV/c2. statistical significance calculated from shape analysis is 5.1 σ, and differential cross section γn→K−Θ+ estimated be 12±2 nb/sr in photon energy range 2.0 2.4 GeV LEPS angular assuming isotropic production γn center-of-mass system. obtained results support existence Θ+.9...
Photoneutron cross sections were measured for ${}^{94}$Mo, ${}^{95}$Mo, ${}^{96}$Mo, ${}^{97}$Mo, ${}^{98}$Mo, and ${}^{100}$Mo near the neutron threshold with quasi-monochromatic laser-Compton scattering $\ensuremath{\gamma}$ rays. The photoneutron data analyzed Skyrme Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random phase approximation (QRPA) model axially symmetric-deformed Gogny HFB QRPA of $E1$ $\ensuremath{\gamma}$-ray strength. Combining strength function constrained by present...
The 12C excitation energy spectra populated in both proton and α-particle inelastic scattering measurements are examined. data indicate the existence of a 2+ state at Ex=9.75(0.15) MeV with width 750(150) keV. It is believed that this corresponds to 7.65 MeV, 0+, Hoyle state, which acts as main path by carbon synthesized stars. A simultaneous R-matrix analysis two sets indicates possesses very large α-reduced width, approaching Wigner limit. This would associated highly clustered structure....
A search for $K^-pp$ bound state (the lightest kaonic nucleus) has been performed using the $\gamma d \rightarrow K^+ \pi^- \rm{X}$ reaction at E$_\gamma$=1.5-2.4 GeV LEPS/SPring-8. The differential cross section of $K^+ \pi^-$ photo-production off deuterium measured first time in this energy region, and a bump structure was searched inclusive missing mass spectrum. statistically significant not observed region from 2.22 to 2.36 GeV/$c^2$, upper limits production were determined be 0.1$-$0.7...
Beam polarization asymmetries for the p(gamma-->,K+)Lambda and p(gamma-->,K+)Sigma(0) reactions are measured first time E(gamma)=1.5-2.4 GeV 0.6<cos((theta(c.m.)(K+))<1.0 by using linearly polarized photons at Laser-Electron-Photon facility SPring-8 (LEPS). The observed positive gradually increase with rising photon energy. data not consistent theoretical predictions based on tree-level effective-Lagrangian approaches. Including new results in development of models is, therefore, crucial...
Photoproduction of a phi meson on protons was studied by means linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections t -|t|min do not increase smoothly as increases but show local maximum around 2.0 angular distributions demonstrate that mesons are photoproduced predominantly helicity-conserving processes, and is likely due unnatural-parity processes.
New measurements of the photoneutron reaction on ${}^{181}\mathrm{Ta}$ have been conducted with AIST-LCS (laser Compton scattering) beam in $7.8\ensuremath{\lesssim}E[\mathrm{MeV}]\ensuremath{\lesssim}12$ energy range. The major advantage present $\ensuremath{\gamma}$-ray experiment is its intense peaking window astrophysical interest, i.e., close to neutron threshold. Details photon beams from laser scattering, counting, and experimental determination cross section are given. data good...
The systematic behavior of the isoscalar giant dipole resonance (ISGDR) in $^{90}\mathrm{Zr}$, $^{116}\mathrm{Sn}$, $^{144}\mathrm{Sm}$, and $^{208}\mathrm{Pb}$ is studied with inelastic $\ensuremath{\alpha}$ scattering at ${E}_{\ensuremath{\alpha}}=386\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$. Multipole-decomposition analysis applied to extract excitation strengths resonances from $(\ensuremath{\alpha},{\ensuremath{\alpha}}^{\ensuremath{'}})$ differential cross sections...
It is shown via a study on $^{26}\mathrm{Mg}$ target that the ($t$,$^{3}\mathrm{He}$) reaction at 115 MeV/nucleon an accurate probe for extracting Gamow-Teller transition strengths. To do so, data are complemented by results from $^{26}\mathrm{Mg}$($^{3}\mathrm{He}$, $t$) 140 allows comparison of $T=2$ analog states excited mirror reactions. Extracted strengths $^{26}\mathrm{Mg}$($t$,$^{3}\mathrm{He}$) and compared with those $^{26}\mathrm{Mg}$($d$,$^{2}\mathrm{He}$)...
The $^{150}\mathrm{Nd}$($^{3}\mathrm{He}$,$t$) reaction at $140$ MeV/u and $^{150}\mathrm{Sm}$($t$,$^{3}\mathrm{He}$) $115$ were measured, populating excited states in $^{150}\mathrm{Pm}$. transitions studied populate intermediate of importance for the (neutrinoless) $\ensuremath{\beta}\ensuremath{\beta}$ decay $^{150}\mathrm{Nd}$ to $^{150}\mathrm{Sm}$. Monopole dipole contributions measured excitation-energy spectra extracted by using multipole decomposition analyses. experimental results...