T. Matsumoto
A5102062728- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Crystallography and molecular interactions
- Neutrino Physics Research
- Particle Detector Development and Performance
- Optical Network Technologies
- Magnetic confinement fusion research
- Medical Imaging Techniques and Applications
- Photonic and Optical Devices
- Atomic and Subatomic Physics Research
- Semiconductor Lasers and Optical Devices
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Chemical Synthesis and Reactions
- Nuclear physics research studies
- Computational Physics and Python Applications
- Muon and positron interactions and applications
- Oxidative Organic Chemistry Reactions
High Energy Accelerator Research Organization
2013-2025
The Graduate University for Advanced Studies, SOKENDAI
2014-2023
European Organization for Nuclear Research
2017
Toho University
2014-2017
Fujitsu Ten (Japan)
2015
Tokyo Metropolitan University
1996-2014
Tokyo Medical and Dental University
2011-2013
Rigaku (Japan)
2011
Yokohama National University
1987-2010
Institute of Particle and Nuclear Studies
2006-2010
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.
The machine commissioning of KEKB started in December 1998 and its operation was terminated at the end June 2010 to upgrade SuperKEKB. In this paper, we summarize history show achievements made there.
We report the observation of a near-threshold enhancement in omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from 253 fb(-1) data sample that contains 275 x 10(6) BB pairs were collected near Upsilon(4S) resonance with Belle detector at KEKB asymmetric energy e(+)e(-) collider. statistical significance is estimated to be greater than 8sigma.
We report the first observation of a charmoniumlike state recoiling from J/psi in inclusive process e+e- -->J/psi+anything at mass (3.943+/-0.006+/-0.006) GeV/c{2}. also observe decay this into D*D[over ] and determine its intrinsic width to be less than 52 MeV/c{2} 90% C.L. These results are obtained 357 fb{-1} data sample collected with Belle detector near Upsilon(4S) resonance, KEKB asymmetric-energy collider.
We report on a search for new resonant states in the process γγ→D¯¯¯D. A candidate C-even charmonium state is observed vicinity of 3.93 GeV/c2. The production rate and angular distribution γγ center-of-mass frame suggest that this previously unobserved χ′c2, 23P2 state.Received 15 December 2005DOI:https://doi.org/10.1103/PhysRevLett.96.082003©2006 American Physical Society
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 a near-threshold enhancement in D(0)D[over](0)pi(0) system from B-->D(0)D[over](0)pi(0)Kappa decays using 414 fb(-1) data sample collected at Upsilon(4S) resonance. The peaks mass M=3875.2+/-0.7(+0.3)/(-1.6) +/-0.8 MeV/c2 and branching fraction for events peak is B(B-->D(0)D[over](0)pi(0)Kappa)=(1.22+/-0.31(+0.23)/(-0.30))x10(-4). were with Belle detector KEKB energy-asymmetric e+ e- collider.
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...
Ultrafast all-optical switching based on the optical Kerr effect in a Sagnac interferometer which consists of dichroic polarization-maintaining fiber coupler and dispersion-shifted loop is reported. This nonlinear switch has advantage high stability originating from completely balanced interfering arms. In addition, because fibers were used, increases power time prevented. Moreover, polarization fluctuation was suppressed due to all-polarization maintaining configuration. The required for...
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 investigated the roles of osteocytes in osteoclastic bone resorption during orthodontic tooth movement using transgenic mice which can be specifically ablated. Because these express receptor for diphtheria toxin on cell surfaces osteocytes, injection ablate their vivo. Injection into significantly increased number ablated alveolar compared with that wild-type or without injection. Increased numbers were observed from day 4 to 12 after bones as well cortical tibiae. applied force days...
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...
A novel all-optical timing-recovery scheme that uses an optical tank circuit is presented. An clock synchronized to incoming data stream generated by extracting line spectral components in the using resonator whose free range equal bit rate. The principle of operation demonstrated a confocal Fabry-Perot-type and fiber-ring-type at 2 Gb/s 324 Mb/s, respectively. Quality factor baseband domain measured shown agree well with theoretical value. workable rate, required source linewidth, stability...
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 the results of several studies Lambda(c)(+)pi(+)pi(-)X final state in continuum e(+)e(-) annihilation data collected by Belle detector. An analysis angular distributions Lambda(c)(2880)(+)-->Sigma(c)(2455)(0,++)pi(+,-) decays strongly favors a Lambda(c)(2880)(+) spin assignment 5/2 over 3/2 or 1/2. find evidence for Lambda(c)(2880)(+)-->Sigma(c)(2520)(0,++)pi(+,-) decay and measure ratio partial widths Gamma(Sigma(c)(2520)pi)/Gamma(Sigma(c)(2455)pi)=0.225+/-0.062+/-0.025. This...
We report measurements of the properties D(+)(sJ)(2317) and D(+)(sJ)(2457) resonances produced in continuum e(+)e(-) annihilation near sqrt[s]=10.6 GeV. The analysis is based on an 86.9 fb(-1) data sample collected with Belle detector at KEKB. determine masses to be M(D(+)(sJ)(2317))=2317.2+/-0.5(stat)+/-0.9(syst) MeV/c(2) M(D(+)(sJ)(2457))=2456.5+/-1.3(stat)+/-1.3(syst) MeV/c(2). observe radiative decay mode D(+)(sJ)(2457)-->D(+)(s)gamma dipion D(+)(sJ)(2457)-->D(+)(s)pi(+)pi(-) their...
We present a measurement of the unitarity triangle angle ${\ensuremath{\phi}}_{3}$ using Dalitz plot analysis three-body decay neutral $D$ meson from ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{D}^{(*)}{K}^{\ifmmode\pm\else\textpm\fi{}}$ process. The method employs interference between ${D}^{0}$ and $\overline{{D}^{0}}$ to extract both weak strong phases. apply this $140\text{ }\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ data sample collected by Belle experiment. uses...
The modulation and differential detection characteristics of optical CPFSK transmission systems are investigated both theoretically experimentally. error rate expressions differentially detected derived by considering phase noise LD's. It is clear that the linewidth requirement less than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.68 m</tex> percent bit rate, where xmlns:xlink="http://www.w3.org/1999/xlink">m</tex> index. performances then...
A high-current, long-pulsed beam operation without loss was demonstrated at the Superconducting rf Test Facility (STF) of High Energy Accelerator Research Organization. The primary purpose STF to validate superconducting radio-frequency (rf) acceleration technology for International Linear Collider (ILC) using accelerator components in line with ILC design. Thus, most critical objective perform operations a pulse length (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...