M. Kobayashi
A5103184163- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Nuclear Physics and Applications
- Quantum chaos and dynamical systems
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- CCD and CMOS Imaging Sensors
- Quantum, superfluid, helium dynamics
- Atomic and Molecular Physics
- Image Processing and 3D Reconstruction
- International Science and Diplomacy
- Magnetic properties of thin films
- Quantum and Classical Electrodynamics
- Parallel Computing and Optimization Techniques
High Energy Accelerator Research Organization
2013-2023
Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering
2016
Universidade de Santiago de Compostela
2014-2015
The University of Tokyo
1991-2014
Dimensional Imaging (United Kingdom)
2013
Tohoku University
1989-2012
Osaka University
1998-2012
Tokyo Metropolitan University
2012
University of Electro-Communications
2012
Kyushu Institute of Technology
2005-2011
In a framework of the renormalizable theory weak interaction, problems CP-violation are studied. It is concluded that no realistic models exist in quartet scheme without introducing any other new fields. Some possible also discussed.
We have studied stars in nuclear emulsion due to the capture at rest of Ξ- hyperons produced (K-, K+) reaction. The sequential weak decay a double hypernucleus (nucleus with S = -2) has been directly observed. is assigned as either 10ΛΛBe or 13ΛΛB. This assignment excludes existence H dibaryon lighter than 2203.7 ±0.7 MeV/c2.
We examine the production and decay of a supersymmetric scalar top t${\ifmmode \tilde{}\else \~{}\fi{}}_{1}$ at ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ colliders such as TRISTAN KEK, Stanford Linear Collider, LEP CERN, based on models with soft breaking. Existing bounds for particles imply that in energy range these would be lighter than other quarks quark. make careful study available modes this scenario. The flavor-changing...
Through an analysis of the masses η and X mesons, possible symmetry breaking terms are introduced, in addition to quark mass term, explicitly constructed from fields. The six-fermion interaction is discussed as one their simplest examples.
Excited states in the $N=102$ isotones $^{166}\mathrm{Gd}$ and $^{164}\mathrm{Sm}$ have been observed following isomeric decay for first time at RIBF, RIKEN. The half-lives of measured to be 950(60) 600(140) ns $^{164}\mathrm{Sm}$, respectively. Based on patterns potential energy surface calculations, including ${\ensuremath{\beta}}_{6}$ deformation, a spin parity ${6}^{\ensuremath{-}}$ has assigned both nuclei. Collective observables are discussed light systematics region, giving insight...
We have studied (K−,K+) reactions from an emulsion target. The S=-2 H dibaryon has been searched for by the analysis of K+ momentum spectrum together with data. No evidence production was observed in mass range 1.90–2.16 GeV/c2. Upper limits cross section are (0.2–0.6)% that quasifree Ξ− at 90% confidence level.Received 9 August 1990DOI:https://doi.org/10.1103/PhysRevLett.65.1729©1990 American Physical Society
We searched for possible signatures of top-quark production in 508 ${e}^{+}{e}^{\ensuremath{-}}$ hadronic annihilation events collected at $\sqrt{s}=52$ GeV by the TOPAZ detector KEK collider TRISTAN. The observed cross section and shape are consistent with standard-model predictions without top quarks. A lower limit (95% confidence level) on mass lightest meson is set 25.8 GeV.
The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and significantly improved the precision on its lifetime determination. From sample 21227 atomic pairs, 4% measurement S-wave $\pi\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1}$ been attained, providing an important test Chiral Perturbation Theory.
We argue how pseudo-Dirac scenario for neutrinos leads to rich neutrino oscillation phenomena, including inside each generation. The is generalized by incorporating generation mixings and formulae the various oscillations are derived. As application we compare with corresponding data. find that observed pattern of mixings, such as almost maximal mixing in atmospheric oscillation, naturally explained Pseudo-Dirac small mixings. We, however, also point out there remain some problems be settled...
Presently scientists are working at Mt. John University Observatory in New Zealand using a technique known as gravitational microlensing to search for dark matter our galaxy. This paper describes the current situation of international collaboration MOA (Microlensing Observations Astrophysics) that was formed by these scientists, together with future plans improve facilities.
It is known that the existing experimental limit for CPT violation rather poor---the 10% level at best. For this reason, we study tests in B decays. We show BB\ifmmode\bar\else\textasciimacron\fi{} mixing as well CP-violating asymmetries can reveal violation. also point out that, with possible violation, further necessary order to obtain value \ensuremath{\Delta}m/\ensuremath{\Gamma} from rate of same-sign dilepton events.
We consider pseudo-Dirac-type neutrinos with Majorana masses which are smaller than their Dirac ones. It is shown that there two possible kinds of resonant neutrino oscillations for each generation, whose interplay provides an economical way to solve the puzzles solar and atmospheric simultaneously.
The results of a search for hydrogen-like atoms consisting $\pi^{\mp}K^{\pm}$ mesons are presented. Evidence $\pi K$ atom production by 24 GeV/c protons from CERN PS interacting with nickel target has been seen in terms characteristic pairs their breakup the same ($178 \pm 49$) and Coulomb final state interaction ($653 42$). Using these analysis yields first value lifetime $\tau=(2.5_{-1.8}^{+3.0})$ fs model-independent measurement S-wave isospin-odd scattering length...