A5016620524- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Radiation Therapy and Dosimetry
- Solar and Space Plasma Dynamics
- Medical Imaging Techniques and Applications
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Quantum, superfluid, helium dynamics
- CCD and CMOS Imaging Sensors
- Atomic and Molecular Physics
- Astro and Planetary Science
- Advanced Optical Sensing Technologies
- Atmospheric Ozone and Climate
- Radioactive Decay and Measurement Techniques
Tohoku University
2014-2023
University of Bonn
2013-2022
University of the Basque Country
2013-2022
Duke University
2022
Campbell Collaboration
2012-2022
Chonnam National University
2018-2022
The University of Tokyo
2001-2020
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
2019
Beihang University
2016-2018
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2018
Using the ``modified DPMJET-III'' model explained in previous paper, we calculate atmospheric neutrino flux. The calculation scheme is almost same as HKKM04 \cite{HKKM2004}, but usage of ``virtual detector'' improved to reduce error due it. Then study uncertainty calculated flux summarizing uncertainties individual components simulation. $K$-production interaction estimated by modifying FLUKA'97 and Fritiof 7.02 so that they also reproduce muon data correctly, with those modified models....
We report cosmic-ray proton and helium spectra in energy ranges of 1-120 GeV nucleon-1 1-54 nucleon-1, respectively, measured by a flight the Balloon-borne Experiment with Superconducting Spectrometer (BESS) 1998. The magnetic rigidity cosmic ray was reliably determined highly precise measurement circular track uniform solenoidal field 1 T. Those were within overall uncertainties ±5% for protons ±10% nuclei including statistical systematic errors.
The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS a recent solar-minimum period. We have detected for first time characteristic peak at 2 GeV originating from interactions with interstellar gas. is reproduced theoretical calculations, implying that propagation models are basically correct and different species undergo universal propagation. Future data still higher statistics will allow us to...
Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons helium nuclei energy ranges, 1–540 GeV 1–250 GeV/n, respectively, flux muons range 0.6–400 GeV/c.
The energy spectra of cosmic-ray low-energy antiprotons ( $\overline{p}$'s) and protons $p$'s) have been measured by BESS in 1999 2000, during a period covering reversal at the solar magnetic field. Based on these measurements, sudden increase $\overline{p}/p$ flux ratio following field was observed, it generally agrees with drift model modulation.
The cosmic-ray hydrogen and helium spectra have been measured by the Balloon Borne Experiment with a Superconducting Solenoid Spectrometer (BESS), which has flown from Lynn Lake, Manitoba, Canada, annually since 1993. BESS experiment provides excellent rigidity measurement precise particle identification large geometric acceptance. We present here nuclei energy 0.2 to 10 GeV nucleon-1 their isotopic composition about 1 for first flight. This simultaneous measurements of secondaries,...
The cross section for e^+e^- \to \eta J/\psi between \sqrt{s}=3.8 GeV/c^2 and 5.3 is measured via initial state radiation using 980 fb^{-1} of data on around the \Upsilon(nS)(n=1,2,3,4,5) resonances collected with Belle detector at KEKB. Two resonant structures \psi(4040) \psi(4160) are observed in invariant mass distribution. Fitting spectrum coherent sum two Breit-Wigner functions, one obtains BR(\psi(4040)\to\eta J/\psi)\cdot\Gamma_{ee}^{\psi(4040)} = (4.8\pm0.9\pm1.4) eV...
We search for lepton-flavor-violating and lepton-number-violating tau decays into a lepton (l = electron or muon) two charged mesons (h, h' pion Kaon) using 854 fb^{-1} of data collected with the Belle detector at KEKB asymmetric-energy e^+e^- collider. obtain 90% confidence level upper limits on to lhh' branching fractions in range (2.0-8.4)*10^{-8}. These results improve upon our previously published by factors about 1.8 average.
The dark photon ${A}^{\ensuremath{'}}$ and the Higgs boson ${h}^{\ensuremath{'}}$ are hypothetical constituents featured in a number of recently proposed sector models. Assuming prompt decays both particles, we search for their production so-called Higgstrahlung channel ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{A}^{\ensuremath{'}}{h}^{\ensuremath{'}}$, with ${h}^{\ensuremath{'}}\ensuremath{\rightarrow}{A}^{\ensuremath{'}}{A}^{\ensuremath{'}}$. We investigate ten exclusive final...
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
We have made a precise measurement of the absolute branching fractions Bs->Ds(*)+ Ds(*)- decays using 121.4 fb-1 data recorded by Belle experiment running on Upsilon(5S) resonance. The results are B(Bs0->Ds+ Ds-) = (0.58 +0.11 -0.09 +-0.13)%, B(Bs0->Ds*+- Ds-+) (1.8 +-0.2 +-0.4)%, and B(Bs0->Ds*+ Ds*-) (2.0 +-0.3 +-0.5)%; sum is B(Bs0->Ds(*)+ (4.3 +-0.4 +-1.0)%. Assuming saturates to CP-even final states, fraction constrains ratio Delta(Gamma_s)/cos(phi_s), where Delta(Gamma_s) difference in...
The absolute fluxes of the cosmic-ray antiprotons at solar minimum are measured in energy range 0.18 to 1.4 GeV, based on 43 events unambiguously detected BESS '95 data. resultant spectrum appears be flat below 1 compatible with a possible admixture primary antiproton component soft spectrum, while possibility secondary alone explaining data cannot excluded present accuracy. Further improvement statistical accuracy and extension planned future flights.
Ultracold neutrons (UCNs) can be bound by the potential of terrestrial gravity and a reflecting mirror. The wave function state has characteristic modulations. We carried out an experiment to observe vertical distribution UCNs above such mirror at Institut Laue-Langevin in 2011. observed modulation is good agreement with that prediction quantum mechanics using Wigner function. spatial resolution detector system estimated 0.7 micro meter. This first observation gravitationally states...
We have studied the hadronic interaction for calculation of atmospheric neutrino flux by summarizing accurately measured muon data and comparing with simulations. find fluxes respond to errors in $\ensuremath{\pi}$-production similarly, compare calculated using HKKM04 [M. Honda, T. Kajita, K. Kasahara, S. Midorikawa, Phys. Rev. D 70, 043008 (2004).] code experimental measurements. The ${\ensuremath{\mu}}^{+}+{\ensuremath{\mu}}^{\ensuremath{-}}$ show good agreement $1\ensuremath{\sim}30\text{...
We have developed a high-resolution cavity-beam position monitor (BPM) to be used at the focal point of ATF2, which is test beam line that now being built demonstrate stable orbit control $\ensuremath{\sim}\mathrm{\text{nanometer}}$ resolution. The design cavity structure was optimized for Accelerator Test Facility (ATF) in various ways. For example, has rectangular shape order isolate two dipole modes orthogonal directions, and relatively thin gap less sensitive trajectory inclination. A...
ATF2 is a final-focus test beam line which aims to focus the low emittance from ATF damping ring vertical size of about 37 nm and demonstrate nanometer level stability. Several advanced diagnostics feedback tools are used. In December 2008, construction installation were completed commissioning started, supported by an international team Asian, European, U.S. scientists. The present status first results described.
We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between CP-violating asymmetries D(±)→K(+)K(-)π(±) and Cabibbo-favored D(s)(±)→K(+)K(-)π(±) K(+)K(-) mass region of ϕ resonance. Using 955 fb(-1) data collected with Belle detector, we obtain A(CP)(D+→ϕπ+)=(+0.51±0.28±0.05)%. The measurement improves sensitivity previous searches more than a factor 5. find no evidence direct violation.