T. Kawasaki
A5107140975- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Geophysics and Sensor Technology
- Seismic Waves and Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Radiation Detection and Scintillator Technologies
- High-pressure geophysics and materials
- Mechanical and Optical Resonators
- Advanced MEMS and NEMS Technologies
- Interconnection Networks and Systems
- Embedded Systems Design Techniques
- Parallel Computing and Optimization Techniques
- Quantum Mechanics and Applications
- Noncommutative and Quantum Gravity Theories
- Aerodynamics and Fluid Dynamics Research
The University of Tokyo
2019-2025
Shanghai Institute for Science of Science
2025
Institute of Science Tokyo
2025
Kitasato University
2016-2023
Tokyo Institute of Technology
2023
Jeonbuk National University
2023
Sun Yat-sen University
2023
Osaka University
2021
Niigata University
2003-2015
RWTH Aachen University
2014
The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio events 0.944±0.016(stat)±0.040(syst) was obtained in 101 days running at the nuclear power plant France, two 4.25 GW(th) reactors. results were from a single 10 m(3) fiducial volume detector located 1050 m cores. flux prediction used Bugey4 measurement after correction for differences core composition. deficit can be...
Abstract KAGRA is a newly built gravitational-wave telescope, laser interferometer comprising arms with length of 3 km, located in Kamioka, Gifu, Japan. was constructed under the ground and it operated using cryogenic mirrors that help reducing seismic thermal noise. Both technologies are expected to provide directions for future telescopes. In 2019, finished all installations designed configuration, which we call baseline KAGRA. For this occasion, present an overview from various viewpoints...
The Double Chooz experiment has observed 8249 candidate electron antineutrino events in 227.93 live days with 33.71 GW-ton-years ($\mathrm{\text{reactor power}}\ifmmode\times\else\texttimes\fi{}\mathrm{\text{detector mass}}\ifmmode\times\else\texttimes\fi{}\mathrm{\text{live time}}$) exposure using a $10.3\text{ }\text{ }{\mathrm{m}}^{3}$ fiducial volume detector located at 1050 m from the reactor cores of nuclear power plant France. expectation case ${\ensuremath{\theta}}_{13}=0$ is 8937...
The Double Chooz experiment presents improved measurements of the neutrino mixing angle θ 13 using data collected in 467.90 live days from a detector positioned at an average distance 1050 m two reactor cores nuclear power plant. Several novel techniques have been developed to achieve significant reductions backgrounds and systematic uncertainties with respect previous publications, whereas efficiency $$ {\overline{\nu}}_e signal has increased. value is measured be sin2 2θ = 0.090 − 0.029 +...
KAGRA is a newly built gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this series of articles, we present an overview the baseline KAGRA, for which finished installing designed configuration 2019. This article describes method calibration (CAL) used reconstructing signals from detector outputs, as well characterization (DET). We also review physical environmental monitors (PEM) system and geophysics (GIF). Both are...
The Double Chooz collaboration presents a measurement of the neutrino mixing angle θ 13 using reactor $$ \overline{\nu_{\mathrm{e}}} observed via inverse beta decay reaction in which neutron is captured on hydrogen. This based 462.72 live days data, approximately twice as much data previous such analysis, collected with detector positioned at an average distance 1050 m from two cores. Several novel techniques have been developed to achieve significant reductions backgrounds and systematic...
Abstract KAGRA is a newly build gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this paper, one of series articles featuring KAGRA, we discuss the science targets projects, considering not only baseline (current design) but also its future upgrade candidates (KAGRA+) for near to middle term ($\sim$5 years).
We present a search for Lorentz violation with 8249 candidate electron antineutrino events taken by the Double Chooz experiment in 227.9 live days of running. This analysis, featuring sidereal time dependence events, is first test invariance using reactor-based source. No variation data and disappearance results are consistent independent oscillations. Under Standard-Model Extension, we set limits on 14 violating coefficients associated transitions between tau flavor, two competitive muon flavor.
The oscillation results published by the Double Chooz Collaboration in 2011 and 2012 rely on background models substantiated reactor-on data. In this analysis, we present a background-model-independent measurement of mixing angle θ13 including 7.53 days reactor-off A global fit observed antineutrino rates for different reactor power conditions is performed, yielding both total rate. are improved significantly data fit, as it provides direct This rate modulation analysis considers candidates...
KAGRA is a second-generation interferometric gravitational-wave detector with 3-km arms constructed at Kamioka, Gifu in Japan. It now its final installation phase, which we call bKAGRA (baseline KAGRA), scientific observations expected to begin late 2019. One of the advantages underground location least 200 m below ground surface, brings small seismic motion low frequencies and high stability detector. Another advantage that it cools down sapphire test mass mirrors cryogenic temperatures...
Double Chooz is unique among modern reactor-based neutrino experiments studying $\bar \nu_e$ disappearance in that data can be collected with all reactors off. In this paper, we present from 7.53 days of reactor-off running. Applying the same selection criteria as used reactor-on oscillation analysis, a measured background rate 1.0$\pm$0.4 events/day obtained. The model for accidentals, cosmogenic $\beta$-$n$-emitting isotopes, fast neutrons cosmic muons, and stopped-$\mu$ decays analysis...
Abstract We have proposed a new approach to search for axion dark matter with an optical ring cavity [Phys. Rev. Lett. 121, 161301 (2018)]. The coupling of photons axions or axion-like particles makes modulated difference in the phase velocity between left- and righthanded photons. Our method is measure this cavity, by measuring resonant frequency two circular polarizations. estimation shows that sensitivity axion-photon constant g γ mass m ≲ 10 −10 eV can be improved several orders...
We have searched for neutrinoless tau lepton decays into three charged leptons using an 87.1 fb^{-1} data sample collected with the Belle detector at KEKB e^+e^- collider. Since number of signal candidate events is compatible that expected from background, we set 90% confidence level upper limits on branching fractions in range (1.9-3.5) x 10^{-7} various decay modes -> l where represents e or mu.
A study on cosmic muons has been performed for the two identical near and far neutrino detectors of Double Chooz experiment, placed at $\sim$120 $\sim$300 m.w.e. underground respectively, including corresponding simulations using MUSIC simulation package. This characterization allowed to measure muon flux reaching both be (3.64 $\pm$ 0.04) $\times$ 10$^{-4}$ cm$^{-2}$s$^{-1}$ detector (7.00 0.05) 10$^{-5}$ one. The seasonal modulation signal also studied observing a positive correlation with...
Modern ground-based gravitational wave (GW) detectors require a complex interferometer configuration with multiple coupled optical cavities.Since achieving the resonances of arm cavities is most challenging among lock acquisition processes, scheme called length stabilization (ALS) had been employed for cavities.We designed new type ALS, which compatible interferometers having long arms like next generation GW detectors.The features ALS are that control simpler than those previous ones and it...
The Double Chooz experiment measures the neutrino mixing angle θ 13 by detecting reactor $$ {\overline{\nu}}_e via inverse beta decay. positron-neutron space and time coincidence allows for a sizable background rejection, nonetheless liquid scintillator detectors would profit from positron/electron discrimination, if feasible in large detector, to suppress remaining background. Standard particle identification, based on dependent profile of photon emission scintillator, can not be used given...