E. Kikutani
A5104470762- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Gyrotron and Vacuum Electronics Research
- Quantum Chromodynamics and Particle Interactions
- Neutrino Physics Research
- High-Energy Particle Collisions Research
- Magnetic confinement fusion research
- Dark Matter and Cosmic Phenomena
- Muon and positron interactions and applications
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Nuclear Physics and Applications
- Research Data Management Practices
- Advanced Data Storage Technologies
- Graphite, nuclear technology, radiation studies
- International Science and Diplomacy
- Atomic and Molecular Physics
- Innovation Policy and R&D
- Advanced NMR Techniques and Applications
- Pulsed Power Technology Applications
- Mechanical and Optical Resonators
- Advanced Frequency and Time Standards
High Energy Accelerator Research Organization
2000-2014
University of Cincinnati
2003
Goethe University Frankfurt
2003
Chinese Academy of Sciences
2002-2003
Aomori University
2003
Hiroshima Institute of Technology
2003
Chuo University
2003
Institute of High Energy Physics
2002
Ehlers-Danlos Society
2000
Tohoku University
1988
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 first observation of B-->Dmacr;D(sJ)(2317) and B-->Dmacr;D(sJ)(2457) decays based on 123.8x10(6) BBmacr; events collected with Belle detector at KEKB. observe D(sJ)(2317) decay to D(s)pi(0) D(sJ)(2457) D(*)(s)pi(0) D(s)gamma final states. also set 90% C.L. upper limits for D(sJ)(2317)-->D(*)(s)gamma, D(sJ)(2457)-->D(*)(s)gamma, D(sJ)(2457)-->D(s)pi(0), D(sJ)(2457)-->D(s)pi(+)pi(-).
We present the first evidence of decay B -→ τ -ντ , using 414 fb -1 data collected at Υ(4S) resonance with Belle detector KEKB asymmetric-energy e + -collider.Events are tagged by fully reconstructing one mesons in hadronic modes.We detect signal a significance 3.5 standard deviations including systematics, and measure branching fraction to be B(B ) = (1.79+0.56 -0.49(stat) +0.46 -0.51 (syst)) × 10 -4 .This implies that fB 0.229 +0.036 -0.031 (stat) +0.034 -0.037 (syst) GeV is direct...
An experiment to search for the production of neutral penetrating particles decaying into electron-positron pairs was performed with a 2.5-GeV electron beam. A total 0.027 C injected tungsten target. No such particle is found. Constraints on coupling constants ${\ensuremath{\alpha}}_{e}$ and ${\ensuremath{\alpha}}_{\ensuremath{\gamma}}$ are given.
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 an improved measurement of CP-violation parameters in B0-->phiK(0)(S), K(+)K(-)K(0)(S), and eta(')K(0)(S) decays based on a 140 fb(-1) data sample collected at the Upsilon(4S) resonance with Belle detector KEKB energy-asymmetric e(+)e(-) collider. One neutral B meson is fully reconstructed one specified decay channels, flavor accompanying identified from its products. for each three modes are obtained asymmetries distributions proper-time intervals between two decays. find that...
We report the observation of flavor-changing neutral current decay B-->K(*)l(+)l(-) and an im-proved measurement B-->Kl(+)l(-), where l represents electron or a muon, with data sample 140 fb(-1) accumulated at Upsilon(4S) resonance Belle detector KEKB. The results for branching fractions are B(B-->K(*)l(+)l(-))=(11.5(+2.6)(-2.4)+/-0.8+/-0.2)x10(-7) B(B-->Kl(+)l(-))=(4.8(+1.0)(-0.9)+/-0.3+/-0.1)x10(-7), first error is statistical, second systematic third from model dependence.
We report the first observation of CP-violating asymmetries in B0 --> pi+pi- decays based on a 140 fb-1 data sample collected at Upsilon(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. reconstruct one neutral B meson as CP eigenstate and identify flavor accompanying from its decay products. apply an unbinned maximum likelihood fit to distribution time intervals between two points. The yields asymmetry amplitudes Apipi = +0.58+/-0.15(stat)+/-0.07(syst) Spipi...
We have performed a search for the lepton-flavor-violating decay tau -> mu gamma using data sample of 86.3fb^{-1} accumulated by Belle detector at KEK. No evidence signal is seen, and we set an upper limit branching fraction B(tau gamma) < 3.1 x 10^{-7} 90% confidence level.
We report the observation of decay B0→π0π0, using a 253 fb−1 data sample collected at Υ(4S) resonance with Belle detector KEKB e+e− collider. The measured branching fraction is B(B0→π0π0)=(2.3+0.4+0.2−0.5−0.3)×10−6, significance 5.8 standard deviations including systematic uncertainties. also make measurement direct CP violating asymmetry in this mode.Received 22 December 2004DOI:https://doi.org/10.1103/PhysRevLett.94.181803©2005 American Physical Society
We present an improved measurement of CP-violating asymmetries in B0→π+π− decays based on a 78fb−1 data sample collected at the Υ(4S) resonance with Belle detector KEKB asymmetric-energy e+e− collider. reconstruct one neutral B meson as CP eigenstate and identify flavor accompanying from inclusive properties its decay products. apply unbinned maximum likelihood fit to distribution time intervals between two points. The yields asymmetry amplitudes Aππ=+0.77±0.27(stat)±0.08(syst)...
We present a measurement of CP-violation parameters in the →bs¯qq penguin transitions (q=s,u,d) based on 78fb−1 data sample collected at Υ(4S) resonance with Belle detector KEKB energy-asymmetric e+e− collider. One neutral B meson is reconstructed φK0S, K+K−K0S, or η′K0S decay channel, and flavor accompanying identified from its products. CP violation for each three modes are obtained asymmetries distributions proper-time intervals between two decays.Received 25 December...
High-speed digital filter systems for bunch-by-bunch feedback have been developed at KEK. A two-tap finite impulse response with simple hardware realizes the functions of a 90\ifmmode^\circ\else\textdegree\fi{} phase shift, suppression static component and delay up to few hundred turns KEKB rings. Difficulties in circuit board, such as trimming timing skews or problem long-term reliability, solved using custom GaAs large-scale integrated circuits which demultiplex multiplex fast...
The history of the KEKB commissioning is characterized by struggles with three obstacles, namely electron-cloud instability, beam-beam blowup and beam current limitations from many reasons. A rapid improvement in luminosity this year (2001) has been made progress each these problems. This report summarizes year's accelerator, since prior days covered other reports.