A5060369845- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Machine Learning in Materials Science
- X-ray Diffraction in Crystallography
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Catalysis and Oxidation Reactions
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Electronic and Structural Properties of Oxides
- Solar and Space Plasma Dynamics
Preferred Networks (Japan)
2022
Tohoku University
2013-2016
Tokai University
2008-2014
The University of Tokyo
2013
We present results from the first phase of KamLAND-Zen double-beta decay experiment, corresponding to an exposure 89.5 kg yr $^{136}\mathrm{Xe}$. obtain a lower limit for neutrinoless half-life ${T}_{1/2}^{0\ensuremath{\nu}}>1.9\ifmmode\times\else\texttimes\fi{}{10}^{25}\text{ }\text{ }\mathrm{yr}$ at 90% C.L. The combined and EXO-200 give ${T}_{1/2}^{0\ensuremath{\nu}}>3.4\ifmmode\times\else\texttimes\fi{}{10}^{25}\text{ C.L., which corresponds Majorana neutrino mass...
The recent long-term shutdown of Japanese nuclear reactors has resulted in a significantly reduced reactor ν¯e flux at KamLAND. This running condition provides unique opportunity to confirm and constrain backgrounds for the oscillation analysis. data set also improved sensitivity other signals, particular ν¯e’s produced β-decays from U238 Th232 within Earth’s interior, whose energy spectrum overlaps with that ν¯e’s. Including constraints on θ13 accelerator short-baseline neutrino...
Abstract Computational material discovery is under intense study owing to its ability explore the vast space of chemical systems. Neural network potentials (NNPs) have been shown be particularly effective in conducting atomistic simulations for such purposes. However, existing NNPs are generally designed narrow target materials, making them unsuitable broader applications discovery. Here we report a development universal NNP called PreFerred Potential (PFP), which able handle any combination...
XMASS, a low-background, large liquid-xenon detector, was used to search for solar axions that would be produced by bremsstrahlung and Compton effects in the Sun. With an exposure of 5.6 ton days liquid xenon, model-independent limit on coupling mass ≪1 keV is |gaee|<5.4×10−11 (90% C.L.), which factor two stronger than existing experimental limit. The bounds axion masses DFSZ KSVZ models are 1.9 250 eV, respectively. In range 10–40 keV, this study most stringent limit, better previously...
We report a measurement of the neutrino-electron elastic scattering rate 862 keV 7Be solar neutrinos based on 165.4 kton-day exposure KamLAND. The observed is 582 +/- 90 (kton-day)^-1, which corresponds to neutrino flux (3.26 0.50) x 10^9 cm^-2s^-1, assuming pure electron flavor flux. Comparing this with standard model prediction and further three mixing, nu_e survival probability 0.66 0.14 determined from KamLAND data. Utilizing global oscillation analysis, we obtain total (5.82 0.98)...
ABSTRACT In the late stages of nuclear burning for massive stars ( M > 8 ⊙ ), production neutrino–antineutrino pairs through various processes becomes dominant stellar cooling mechanism. As star evolves, energy these neutrinos increases and in days preceding supernova a significant fraction emitted electron anti-neutrinos exceeds threshold inverse beta decay on free hydrogen. This is golden channel liquid scintillator detectors because coincidence signature allows reductions background...
KamLAND-Zen reports on a preliminary search for neutrinoless double-beta decay with 136Xe based 114.8 live-days after the purification of xenon loaded liquid scintillator. In this data, problematic 110mAg background peak identified in previous searches is reduced by more than factor 10. By combining pre- and post-purification we obtain lower limit 0νββ half-life T1/20ν>2.6×1025 yr at 90% C.L. The sensitivity will be enhanced additional low data purification. Prospects further improvements...
The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center or next to large low-background liquid scintillator detector. generator will produced by Russian reprocessing plant PA Mayak as early 2014, transported Japan, in Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) 2015. KamLAND's 13 m diameter target volume provides suitable environment measure energy position dependence of detected...
We present a search for the proton decay mode $p \rightarrow \overline{\nu} K^{+}$ based on an exposure of 8.97 kton-years in KamLAND experiment. The liquid scintillator detector is sensitive to successive signals from with unique kinematics, which allow us achieve detection efficiency 44%, higher than previous searches water Cherenkov detectors. find no evidence decays this mode. expected background, dominated by atmospheric neutrinos, $0.9 \pm 0.2$ events. nonbackground-subtracted limit...
We search for electron anti-neutrinos ($\overline{\nu}_e$) from long and short-duration gamma-ray bursts~(GRBs) using data taken by the KamLAND detector August 2002 to June 2013. No statistically significant excess over background level is found. place tightest upper limits on $\overline{\nu}_e$ fluence GRBs below 7 MeV first constraints relation between luminosity effective temperature.