A5039842881- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Atomic and Molecular Physics
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Neutrino Physics Research
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Rare-earth and actinide compounds
- Medical Imaging Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Inorganic Fluorides and Related Compounds
- Astronomy and Astrophysical Research
- Solid-state spectroscopy and crystallography
Osaka University
2015-2025
Okayama University
2020
University of Tokyo Hospital
2018
Tohoku University Hospital
2018
Campbell Collaboration
2017
University of Notre Dame
2007-2016
Kyoto University
2004-2013
Niigata University
2012
Konan University
2004-2010
International Christian University
1995-2010
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.
A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from Xi(-) hyperon nuclear capture at rest. The mass and Lambda-Lambda interaction energy DeltaB(LambdaLambda) have measured for first time devoid ambiguities due to possibilities excited states. value 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that weakly attractive.
A benchmark experiment on 208Pb shows that polarized proton inelastic scattering at very forward angles including 0{\deg} is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic (M1) modes in nuclei over broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads neutron skin thickness r_skin = 0.156+0.025-0.021 fm derived within mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry its...
The E885 Collaboration utilized the 1.8GeV/cK− beam line at Alternating Gradient Synchrotron (AGS) to accumulate greater than 10 times world's existing data sample of (K−,K+) events on carbon. A total about 3×105(K−,K+) were collected and analyzed. Ξ hypernuclear states are expected be produced through reaction K−+12→CK++12ΞBe. signal could also result from direct production 11ΛBe+Λ without a distinct intermediate state. measured missing-mass spectrum indicates existence below threshold for...
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.
Cross sections and analyzing powers for polarized proton elastic scattering from $^{58}\mathrm{Ni}$, $^{204,206,208}\mathrm{Pb}$ were measured at intermediate energy ${E}_{p}=295$ MeV. An effective relativistic Love-Franey interaction is tuned to reproduce $^{58}\mathrm{Ni}$ data within the framework of impulse approximation. The neutron densities lead isotopes are deduced using model-independent sum-of-Gaussians distributions. Their error envelopes estimated by a new...
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...
A hybrid experiment with nuclear emulsion and scintillating-fiber detectors (KEK-E373) has been performed to search for double-strangeness systems. Among about 10${}^{3}$ events of ${\ensuremath{\Xi}}^{\ensuremath{-}}$ hyperons captured at rest by nuclei, we have observed four which clearly show the topology cascade weak decays double-$\ensuremath{\Lambda}$ hypernuclei including ``Nagara'' event. Regarding Nagara event, values two-$\ensuremath{\Lambda}$ binding energy...
The electric dipole strength distribution in 120Sn between 5 and 22 MeV has been determined at RCNP Osaka from a polarization transfer analysis of proton inelastic scattering E_0 = 295 forward angles including 0{\deg}. Combined with photoabsorption data an polarizability \alpha_D(120Sn) 8.93(36) fm^3 is extracted. as isovector observable par excellence carries direct information on the nuclear symmetry energy its density dependence. correlation new value well established \alpha_D(208Pb)...
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...
Differential cross sections for γp→K+Λ(1405) and γp→K+Σ0(1385) reactions have been measured in the photon energy range from 1.5 to 2.4 GeV angular of 0.8<cos(Θ)<1.0 K+ scattering angle center-of-mass system. This data is first measurement Λ(1405) photoproduction section. The line shapes Σ+π− Σ−π+ decay modes were different with each other, indicating a strong interference isospin 0 1 terms Σπ amplitudes. ratios production Σ0(1385) two ranges: near threshold (1.5<Eγ<2.0 GeV) far it...
Scattering of protons several hundred MeV is a promising new spectroscopic tool for the study electric dipole strength in nuclei. A case 208Pb shows that at very forward angles J^pi = 1- states are strongly populated via Coulomb excitation. separation from nuclear excitation other modes achieved by multipole decomposition analysis experimental cross sections based on theoretical angular distributions calculated within quasiparticle-phonon model. The B(E1) transition distribution extracted...
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...
The electric dipole strength in 120Sn has been extracted from proton inelastic scattering experiments at E_p = 295 MeV and forward angles including 0 degree. Below neutron threshoild it differs the results of a 120Sn(gamma,gamma') experiment peaks an excitation energy 8.3 MeV. total corresponds to 2.3(2)% energy-weighted sum rule is more than three times larger what observed with (gamma,gamma') reaction. This implies strong fragmentation E1 and/or small ground state branching ratios excited...
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.