T. Matsuda
A5084000351- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Aortic Disease and Treatment Approaches
- Cardiac and Coronary Surgery Techniques
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Quantum, superfluid, helium dynamics
- Congenital Heart Disease Studies
- Cosmology and Gravitation Theories
- Scientific Computing and Data Management
- International Science and Diplomacy
- Seismology and Earthquake Studies
University of Miyazaki
2015-2024
A. Alikhanyan National Laboratory
2023
Ruhr University Bochum
2023
University of Illinois System
2023
LIP - Laboratory of Instrumentation and Experimental Particle Physics
2023
Yamagata University Hospital
2023
Charles University
2023
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2023
University of Trieste
2023
University of Aveiro
2020-2023
We report a measurement of the ratio ${\cal R}(D^*) = {\cal B}(\bar{B}^0 \rightarrow D^{*+} \tau^- \bar{\nu}_{\tau})/{\cal \ell^- \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or muon. The results are based on data sample containing $772\times10^6$ $B\bar{B}$ pairs recorded at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+ e^-$ collider. select $B^0 \bar{B}^0$ by reconstructing both $B$ mesons in semileptonic decays to $D^{*\mp} \ell^{\pm}$. measure R}(D^*)= 0.302 \pm...
With the full data sample of $772 \times 10^6$ $B{\bar B}$ pairs recorded by Belle detector at KEKB electron-positron collider, decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ is studied with hadronic $\tau$ decays $\tau^- \pi^- \nu_\tau$ and \rho^- \nu_\tau$. The polarization $P_\tau(D^*)$ in two-body measured, as well ratio branching fractions $R(D^{*}) = \mathcal{B}(\bar {B} \bar{\nu}_\tau) / \mathcal{B}(\bar{B} \ell^- \bar{\nu}_\ell)$, where $\ell^-$ denotes an electron or a muon....
We present a measurement of ${R}_{{K}^{*}}$, the branching fraction ratio $\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})/\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{e}^{+}{e}^{\ensuremath{-}})$, for both charged and neutral $B$ mesons. The case ${R}_{{K}^{*+}}$ is first ever performed. In addition, we report absolute fractions individual modes in bins squared dilepton invariant mass ${q}^{2}$. analysis based on data sample $711\text{...
We have measured the spin-dependent structure function g1p in inclusive deep-inelastic scattering of polarized muons off protons, kinematic range 0.003<x<0.7 and 1GeV2<Q2<60GeV2. A next-to-leading order QCD analysis is used to evolve g1p(x,Q2) a fixed Q02. The first moment at Q02=10GeV2 Γ1p=0.136±0.013 (stat) ±0.009 (syst) ±0.005 (evol). This result below prediction Ellis-Jaffe sum rule by more than two standard deviations. singlet axial charge a0 found be 0.28±0.16. In Adler-Bardeen...
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...
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...
We perform a full amplitude analysis of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}D\overline{D}$, where $D$ refers to either ${D}^{0}$ or ${D}^{+}$. A new charmoniumlike state ${X}^{*}(3860)$ that decays $D\overline{D}$ is observed with significance $6.5\ensuremath{\sigma}$. Its mass $({3862}_{\ensuremath{-}32}^{+26}{\text{ }}_{\ensuremath{-}13}^{+40})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and its width $({201}_{\ensuremath{-}67}^{+154}{\text{...
We report measurements of production cross sections for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>ρ</a:mi><a:mo>+</a:mo></a:msup></a:math>, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>ρ</c:mi><c:mn>0</c:mn></c:msup></c:math>, <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>ω</e:mi></e:math>, <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"...
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.
Based on 58 million BESII J/psi events, the bar{K}^*(892)^0K^+pi^- channel in K^+K^-pi^+pi^- is studied. A clear low mass enhancement invariant spectrum of K^+pi^- observed. The does not come from background other decay channels, nor phase space. Two independent partial wave analyses have been performed. Both favor that kappa, an isospinor scalar resonant state. average and width kappa two are 878 +- 23^{+64}_{-55} MeV/c^2 499 52^{+55}_{-87} MeV/c^2, respectively, corresponding to a pole at...
Using a data sample of $980\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation taken with the Belle detector operating at KEKB asymmetric-energy collider, we report results study excited ${\mathrm{\ensuremath{\Xi}}}_{c}$ states that decay, via emission photons and/or charged pions, into ${\mathrm{\ensuremath{\Xi}}}_{c}^{0}$ or ${\mathrm{\ensuremath{\Xi}}}_{c}^{+}$ ground state charmed-strange baryons. We present new measurements masses all members...
Using data collected with the Belle detector at KEKB asymmetric-energy $e^+e^-$ collider, we measure energy dependence of $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections from thresholds up to $11.02\,$GeV. We find clear $\Upsilon(10860)$ and $\Upsilon(11020)$ peaks little or no continuum contribution. study resonant substructure $\Upsilon(11020) transitions evidence that they proceed entirely via intermediate isovector states $Z_b(10610)$ $Z_b(10650)$. The relative fraction these is...
We present the first measurements of absolute branching fractions ${\mathrm{\ensuremath{\Xi}}}_{c}^{0}$ decays into ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, $\mathrm{\ensuremath{\Lambda}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, and $p{K}^{\ensuremath{-}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ final states. The are made using a dataset comprising $(772\ifmmode\pm\else\textpm\fi{}11)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected...
In the bottomonium sector, hindered magnetic dipole transitions between P-wave states <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>h</a:mi></a:mrow><a:mrow><a:mi>b</a:mi></a:mrow></a:msub><a:mo stretchy="false">(</a:mo><a:mn>2</a:mn><a:mi>P</a:mi><a:mo stretchy="false">)</a:mo><a:mo stretchy="false">→</a:mo><a:msub><a:mrow><a:mi>χ</a:mi></a:mrow><a:mrow><a:mi>b</a:mi><a:mi>J</a:mi></a:mrow></a:msub><a:mo...
We report the discovery of ${\mathrm{\ensuremath{\Xi}}}_{c}(3055{)}^{0}$, observed by its decay into final-state $\mathrm{\ensuremath{\Lambda}}{D}^{0}$, and present first observation evidence decays ${\mathrm{\ensuremath{\Xi}}}_{c}(3055{)}^{+}$ ${\mathrm{\ensuremath{\Xi}}}_{c}(3080{)}^{+}$ $\mathrm{\ensuremath{\Lambda}}{D}^{+}$. also perform a combined analysis $\mathrm{\ensuremath{\Lambda}}{D}^{+}$ with ${\mathrm{\ensuremath{\Sigma}}}_{c}^{++}{K}^{\ensuremath{-}}$...
We report the first observation of $$\Xi _{c}(2930)^0$$ charmed-strange baryon with a significance greater than 5 $$\sigma $$ . The is found in its decay to $$K^- \Lambda _{c}^+$$ $$B^{-} \rightarrow K^{-} _{c}^{+} \bar{\Lambda }_{c}^{-}$$ decays. measured mass and width are $$[2928.9 \pm 3.0(\mathrm stat.)^{+0.9}_{-12.0}(\mathrm syst.)]$$ MeV/ $$c^{2}$$ $$[19.5 8.4(\mathrm stat.) ^{+5.9}_{-7.9}(\mathrm MeV, respectively, product branching fraction $$\mathcal{B}(B^{-} \Xi _{c}(2930)^0...
A bstract We report a new measurement of the e + − → ϒ( nS ) π ( n = 1 , 2 3) cross sections at energies from 10 . 52 to 11 02 GeV using data collected with Belle detector KEKB asymmetric-energy collider. observe structure in energy dependence sections; if described by Breit-Wigner function its mass and width are found be $$ M=\left(10752.7\pm {5.9}_{-1.1}^{+0.7}\right)\mathrm{MeV}/{c}^2 <mml:math...
Differential cross sections and photon-beam asymmetries have been measured for the gamma n --> K+ Sigma- p K+Sigma0 reactions separately using liquid deuterium hydrogen targets with incident linearly polarized photon beams of E = 1.5-2.4 GeV at 0.6 < cos ThetacmK< 1. The section ratio sigma Sigma-/sigma Sigma0, expected to be 2 on basis isospin 1/2 exchange, is found close For reaction, large positive are observed, indicating dominance K* exchange. difference between Sigma0 cannot explained...
Differential cross sections and photon-beam asymmetries for the gamma p -> K+ Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from threshold to 2.4 GeV 0.6<cos(theta)<1. A new bump structure was found W=2.11 in sections. The is not well reproduced by theoretical calculations introducing a nucleon resonance J<=3/2. This result suggests that might be produced possibly J>=5/2 or process, example an interference effect phi photoproduction having similar
We measure the inclusive production cross sections of hyperons and charmed baryons from ${e}^{+}{e}^{\ensuremath{-}}$ annihilation using a $800\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample taken near $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance with Belle detector at KEKB asymmetric-energy collider. The feed-down contributions heavy particles are subtracted our data, direct presented for first time. divided by number spin states $S=\ensuremath{-}1$ follow an exponential...
Using a data sample of $921.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the Belle detector, we study process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}_{s}^{+}{D}_{s1}(2536{)}^{\ensuremath{-}}+\mathrm{c}.\mathrm{c}.$ via initial-state radiation. We report first observation vector charmoniumlike state decaying to ${D}_{s}^{+}{D}_{s1}(2536{)}^{\ensuremath{-}}+\mathrm{c}.\mathrm{c}.$ significance $5.9\ensuremath{\sigma}$, including systematic uncertainties. The...
The helicity dependence of the total cross section for γ→p→→nπ+π0 reaction has been measured first time at incident photon energies from 400 to 800 MeV. measurement was performed with large acceptance detector DAPHNE tagged beam facility MAMI accelerator in Mainz. This channel is found be excited predominantly when and proton have a parallel spin orientation, due intermediate production D13 resonance.