A5021842167- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Dark Matter and Cosmic Phenomena
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Black Holes and Theoretical Physics
- Nuclear physics research studies
- Superconducting Materials and Applications
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Scientific Computing and Data Management
- CCD and CMOS Imaging Sensors
- Advancements in Semiconductor Devices and Circuit Design
- Radiation Detection and Scintillator Technologies
- Particle accelerators and beam dynamics
- Integrated Circuits and Semiconductor Failure Analysis
- Radioactive Decay and Measurement Techniques
- Atomic and Molecular Physics
High Energy Accelerator Research Organization
2013-2024
The Graduate University for Advanced Studies, SOKENDAI
2015-2021
Osaka University
2001-2014
University of Tsukuba
2007-2010
Children's Defense Fund
2010
Nagoya University
2008
Princeton University
2008
Hanyang University
2008
Cornell University
2008
National United University
2008
We report the observation of a narrow charmoniumlike state produced in exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has mass 3872.0+/-0.6(stat)+/-0.5(syst) MeV, value that is very near M(D0)+M(D(*0)) threshold. The results are based on an analysis 152M B-Bmacr; events collected at Upsilon(4S) resonance Belle detector KEKB collider. signal statistical significance excess 10sigma.
A distinct peak is observed in the ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ invariant mass distribution near 4.43 GeV $B\ensuremath{\rightarrow}K{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ decays. fit using a Breit-Wigner resonance shape yields and width of $M=4433\ifmmode\pm\else\textpm\fi{}4(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}$...
The cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}(2S)$ between threshold and $\sqrt{s}=5.5\text{ }\text{ }\mathrm{GeV}$ is measured using $673\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data on off the $\ensuremath{\Upsilon}(4S)$ resonance collected with Belle detector at KEKB. Two resonant structures are observed in...
The cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ between 3.8 and $5.5\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ is measured using a $548\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected on or near the $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector at KEKB. A peak $4.25\text{ }\mathrm{GeV}/{c}^{2}$, corresponding to so called $Y(4260)$, observed. In addition, there another...
We report the first observation of two charmed strange baryons that decay into Lambda(c)(+)Kappa(-)pi(+). The broader states is measured to have a mass 2978.5+/-2.1+/-2.0 MeV/c2 and width 43.5+/-7.5+/-7.0 MeV/c2. narrow state are be 3076.7+/-0.9+/-0.5 MeV/c;{2} 6.2+/-1.2+/-0.8 MeV/c2, respectively. also perform search for isospin partner Lambda(c)(+)Kappa(0)/(s)pi(-) observe significant signal at 3082.8+/-1.8+/-1.5 data used this analysis were accumulated or near Upsilon(4S) resonance, using...
We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in energy range 1.8 GeV < or = E*gamma 2.8 GeV, covering 95% total spectrum. Using 140 fb(-1), we obtain B(b sgamma) (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where errors are statistical, systematic, and from theory corrections. also measure first second moments photon spectrum above (Egamma) 2.292+/-0.026+/-0.034 (E2gamma) - (Egamma)2 0.0305+/-0.0074+/-0.0063 GeV2, statistical systematic.
The Collins effect connects transverse quark spin with a measurable azimuthal dependence in the yield of hadronic fragments around quark's momentum vector. Using two different reconstruction methods, we find evidence statistically significant asymmetries for charged pion pairs e(+)e(-) annihilation at center-of-mass energy 10.52 GeV, which can be attributed to polarization primordial quarks. measurement was performed using sample 79 x 10(6) events collected Belle detector.
We observe evidence for D0−¯¯¯D0 mixing by measuring the difference in apparent lifetime when a D0 meson decays to CP eigenstates K+K− and π+π− it final state K−π+. find relative of lifetimes yCP be [1.31±0.32(stat)±0.25(syst)]%, 3.2 standard deviations from zero. also search asymmetry between ¯¯¯D0 decays; no violation is found. These results are based on 540 fb−1 data recorded Belle detector at KEKB e+e− collider.Received 31 March 2007DOI:https://doi.org/10.1103/PhysRevLett.98.211803©2007...
We report the first observation of e+e−→Υ(1S)π+π−, Υ(2S)π+π−, and evidence for e+e−→Υ(3S)π+π−, Υ(1S)K+K−, near peak Υ(5S) resonance at s∼10.87 GeV. The results are based on a data sample 21.7 fb−1 collected with Belle detector KEKB e+e− collider. Attributing signals to resonance, partial widths Γ(Υ(5S)→Υ(1S)π+π−)=0.59±0.04(stat)±0.09(syst) MeV Γ(Υ(5S)→Υ(2S)π+π−)=0.85±0.07(stat)±0.16(syst) obtained from observed cross sections. These values exceed by more than 2 orders magnitude previously...
We report a study of the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{D}^{(*)}{\overline{D}}^{(*)}$. In $J/\ensuremath{\psi}{D}^{*}{\overline{D}}^{*}$ we observe significant enhancement in ${D}^{*}{\overline{D}}^{*}$ invariant mass spectrum, which interpret as new charmoniumlike state and denote $X(4160)$. The $X(4160)$ parameters are $M=({4156}_{\ensuremath{-}20}^{+25}\ifmmode\pm\else\textpm\fi{}15)\text{ }\text{ }\mathrm{MeV}/{c}^{2}$...
The Collins effect connects transverse quark spin with a measurable azimuthal asymmetry in the yield of hadronic fragments around quark's momentum vector. Using two different reconstruction methods we measure statistically significant asymmetries for charged pion pairs ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at center-of-mass energies 10.52 GeV and 10.58 GeV, which can be attributed to fragmentation primordial quarks components. measurement was performed using data set $547\text{ }\text{...
We report the observation of a new $D_{sJ}$ meson produced in $B^{+} \to \bar{D}^{0} D_{sJ} D^{0} K^{+}$. This state has mass $M=2708 \pm 9 ^{+11}_{-10} \rm{MeV}/{\it c}^{2}$, width $\Gamma = 108 23 ^{+36}_{-31} ~\rm{MeV}/ {\it c}^{2}$ and $1^{-}$ spin-parity. The results are based on an analysis 449 million $B\bar{B}$ events collected at $\Upsilon(4S)$ resonance with Belle detector KEKB asymmetric-energy $e^{+} e^{-}$ collider.
We report results on the Dalitz analysis of three-body charmless B+→K+π+π− and B+→K+K+K− decays based a 140 fb−1 data sample collected with Belle detector. Measurements branching fractions for quasi-two-body to scalar-pseudoscalar states: B+→f0(980)K+, B+→K∗0(1430)0π+, vector-pseudoscalar B+→K∗(892)0π+, B+→ρ0K+, B+→ϕK+ are presented. Upper limits some pseudoscalar-tensor final states reported. also measurement B+→χc0K+ fraction in two χc0 channels: χc0→π+π− χc0→K+K−.8 MoreReceived 23...
We report an observation of the decay $B^0\to D^{*-} \tau^+ \nu_{\tau}$ in a data sample containing $535\times10^6$ $B\bar{B}$ pairs collected with Belle detector at KEKB asymmetric-energy $e^+e^-$ collider. find signal significance 5.2 standard deviations and measure branching fraction $\mathcal{B}(B^0\to \tau ^+ \nu_{\tau})=(2.02 ^{+0.40}_{-0.37} (stat) \pm 0.37 (syst)) % $. This is first exclusive $B$ $b \to c transition.
We report results on a Dalitz analysis of three-body charmless ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ decay including searches for direct $CP$ violation. the first observation ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{f}_{2}(1270){K}^{\ifmmode\pm\else\textpm\fi{}}$ with statistical significance above $6\ensuremath{\sigma}$. also...
We report a measurement of D0-D0bar mixing in D0->Ks pi+ pi- decays using time-dependent Dalitz plot analysis. first assume CP conservation and subsequently allow for violation. The results are based on 540 fb$^{-1}$ data accumulated with the Belle detector at KEKB $e^+e^-$ collider. Assuming negligible violation, we measure parameters $x=(0.80\pm0.29^{+0.09 +0.10}_{-0.07 -0.14})%$ $y=(0.33\pm0.24^{+0.08 +0.06}_{-0.12 -0.08})%$, where errors statistical, experimental systematic, systematic...
We report a measurement of the exclusive e+e−→D(*)±D*∓ cross section as function center-of-mass energy near D(*)±D*∓ threshold with initial-state radiation. A partial reconstruction technique is used to increase efficiency and suppress background. The analysis based on data sample collected Belle detector an integrated luminosity 547.8 fb−1.Received 12 January 2007DOI:https://doi.org/10.1103/PhysRevLett.98.092001©2007 American Physical Society
We present the first measurement of decay amplitudes in B→φK* and measurements branching fractions B→φK(*) decays based on 78.1 fb−1 data recorded at Υ(4S) resonance with Belle detector KEKB e+e− storage ring. The for different φK*0 helicity states are measured from angular distributions final state particles transversity basis. longitudinal transverse complex |A0|2=0.43±0.09±0.04, |A⊥|2=0.41±0.10±0.04, arg(A∥)=−2.57±0.39±0.09, arg(A⊥)=0.48±0.32±0.06. direct CP-violating asymmetries found to...
We present measurements of decay amplitudes and triple-product correlations in $B\ensuremath{\rightarrow}\ensuremath{\phi}{K}^{*}$ decays based on $253\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data recorded at the $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector KEKB ${e}^{+}{e}^{\ensuremath{-}}$ storage ring. The for three different helicity states are determined from angular distributions final-state particles. longitudinal polarization found to be...
We report on a high statistics measurement of the cross section process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ in ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ invariant mass range $0.8\text{ }\text{ }\mathrm{GeV}/{c}^{2}<W<1.5\text{ }\mathrm{GeV}/{c}^{2}$ with $85.9\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data collected at $\sqrt{s}=10.58\text{ }\mathrm{GeV}$ and 10.52 GeV Belle detector. A...