A5046912484- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Atmospheric Ozone and Climate
- Superconducting Materials and Applications
- Scientific Research and Discoveries
- Radioactive contamination and transfer
- Muon and positron interactions and applications
- Solar and Space Plasma Dynamics
- Radioactivity and Radon Measurements
- Crystal Structures and Properties
- Particle Accelerators and Free-Electron Lasers
- Radioactive Decay and Measurement Techniques
Okayama University
2015-2025
Okayama University of Science
2015-2024
The University of Tokyo
2015-2024
Kavli Institute for the Physics and Mathematics of the Universe
2014-2024
Institute for Cosmic Ray Research
2024
University of Toyama
2024
RIKEN
2024
National Astronomical Observatory of Japan
2024
Pandora (United States)
2022
Kobe University
2017-2021
We present an analysis of atmospheric neutrino data from a 33.0 kton yr (535-day) exposure the Super-Kamiokande detector. The exhibit zenith angle dependent deficit muon neutrinos which is inconsistent with expectations based on calculations flux. Experimental biases and uncertainties in prediction fluxes cross sections are unable to explain our observation. consistent, however, two-flavor...
Solar neutrino measurements from 1258 days of data the Super-Kamiokande detector are presented. The based on recoil electrons in energy range 5.0--20.0 MeV. measured solar flux is $2.32\ifmmode\pm\else\textpm\fi{}0.03(\mathrm{stat}{)}_{\ensuremath{-}0.07}^{+0.08}(\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{6}{\mathrm{cm}}^{\ensuremath{-}2}{\mathrm{s}}^{\ensuremath{-}1}$, which $45.1\ifmmode\pm\else\textpm\fi{}0.5(\mathrm{stat}{)}_{\ensuremath{-}1.4}^{+1.6}(\mathrm{syst})%$ that...
The K2K experiment observes indications of neutrino oscillation: a reduction $\nu_\mu$ flux together with distortion the energy spectrum. Fifty-six beam events are observed in Super-Kamiokande (SK), 250 km from production point, an expectation $80.1^{+6.2}_{-5.4}$. Twenty-nine one ring $\mu$-like used to reconstruct spectrum, which is better matched expected spectrum oscillation than without. probability that at SK explained by statistical fluctuation without less 1%.
We present a combined analysis of fully-contained, partially-contained and upward-going muon atmospheric neutrino data from 1489 d exposure the Super-Kamiokande detector. The samples span roughly five decades in energy, 100 MeV to 10 TeV. A detailed Monte Carlo comparison is described presented. fit expectation, found be consistent with oscillations ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\leftrightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ ${sin}^{2}2\ensuremath{\theta}>0.92$...
The first results of the solar neutrino flux measurement from Super-Kamiokande are presented. shown here obtained data taken between 31 May 1996, and 23 June 1997. Using our recoil electrons with energies above 6.5 MeV, we infer total ${}^{8}\mathrm{B}$ neutrinos to be $2.42\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{stat}{)}_{\ensuremath{-}0.07}^{+0.10}(\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{6}\mathrm{cm}{}^{\ensuremath{-}2}{\mathrm{s}}^{\ensuremath{-}1}$. This result is...
Results from 1036 days of solar neutrino data accumulated in the upgraded Kamiokande detector (Kamiokande III) are presented. The $^{8}\mathrm{B}$ flux observed III is ${2.82}_{\ensuremath{-}0.24}^{+0.25}$ (stat) \ifmmode\pm\else\textpm\fi{} 0.27 (syst) \ifmmode\times\else\texttimes\fi{} ${10}^{6}$ ${\mathrm{cm}}^{\ensuremath{-}2}$${\mathrm{s}}^{\ensuremath{-}1}$; combined II and (2079 total) 2.80 0.19 0.33 ${\mathrm{cm}}^{\ensuremath{-}2}$${\mathrm{s}}^{\ensuremath{-}1}$, which 49% to 64%...
We report the result of a search for neutrino oscillations using precise measurements recoil electron energy spectrum and zenith angle variations solar flux from 1258 days neutrino-electron scattering data in Super-Kamiokande. The absence significant variation distortion places strong constraints on mixing mass difference flux-independent way. Using Super-Kamiokande measurement addition, two allowed regions at large are found.Received 19 March...
Muon neutrino disappearance probability as a function of flight length L over energy E was studied. A dip in the L/E distribution observed data, predicted from sinusoidal flavor transition oscillation. The constrained nu_mu <-> nu_tau oscillation parameters; 1.9x10^-3 < Delta m^2 3.0x10^-3 eV^2 and \sin^2(2theta) > 0.90 at 90% confidence level.
A total of 614 upward throughgoing muons minimum energy 1.6 GeV are observed by Super-Kamiokande during 537 detector live days. The measured muon flux is [1.74±0.07(stat)±0.02(sys)]×10−13cm−2s−1sr−1 compared to an expected [1.97±0.44(theor)]×10−13cm−2s−1sr−1. absolute in agreement with the prediction within errors. However, zenith-angle dependence does not agree no-oscillation predictions. distortion shape consistent νμ↔ντ oscillation hypothesis sin22θ>0.4 and 1×10−3<Δm2<1×10−1eV2 at 90%...
A direct measurement of the 0.862 MeV 7Be solar neutrino interaction rate performed with Borexino detector at Laboratori Nazionali del Gran Sasso yields 46.0$\pm1.5_{\rm stat}$$^{+1.6}_{-1.5\,\rm syst}$ counts/day/(100 tons). Our result is first a sub-MeV an accuracy better than 5%. The hypothesis no oscillation for neutrinos rejected 4.9$\sigma$ C.L. Using latest Standard Solar Model (SSM) flux predictions, leads directly to precise determination survival probability $\nu_e$'s in vacuum,...
From an exposure of 25.5 kiloton-years the Super-Kamiokande detector, 900 muon-like and 983 electron-like single-ring atmospheric neutrino interactions were detected with momentum pe>100 MeV/c, pμ>200 visible energy less than 1.33 GeV. Using a detailed Monte Carlo simulation, ratio (μ/e)DATA/(μ/e)MC was measured to be 0.61±0.03(stat.)±0.05(sys.), consistent previous results from Kamiokande, IMB Soudan-2 experiments, smaller expected theoretical models production.
The details of Super-Kamiokande-I’s solar neutrino analysis are given. Solar measurement in Super-Kamiokande is a high statistics collection 8B neutrinos via neutrino-electron scattering. method and results the 1496 day data sample presented. final oscillation for presented also.50 MoreReceived 30 August 2005DOI:https://doi.org/10.1103/PhysRevD.73.112001©2006 American Physical Society
The results of the second phase Super-Kamiokande solar neutrino measurement are presented and compared to first phase. flux spectrum time variation as well oscillation statistically consistent with do not show spectral distortion. time-dependent combined phases coincides full period cycle 23 shows no correlation activity. measured $^{8}\mathrm{B}$ total is...
The flavor ratio of the atmospheric neutrino flux and its zenith angle dependence have been studied in multi-GeV energy range using an exposure 25.5 kiloton-years Super-Kamiokande detector. By comparing data to a detailed Monte Carlo simulation, (μ/e)DATA/(μ/e)MC was measured be 0.66±0.06(stat.)±0.08(sys.). In addition, strong distortion shape μ-like event distribution observed. number upward downward events found 0.52+0.07−0.06(stat.)±0.01(sys.), with expected value...
The results of the third phase Super-Kamiokande solar neutrino measurement are presented and compared to first second results. With improved detector calibrations, a full simulation, analysis methods, systematic uncertainty on total flux is estimated be ?2.1%, which about two thirds for Super-Kamiokande. observed 8B in 5.0 20 MeV electron energy region 2.32+/-0.04 (stat.)+/-0.05 (sys.) *10^6 cm^-2sec^-1, agreement with previous measurements. A combined oscillation carried out using SK-I, II,...
We propose the Hyper-Kamiokande (Hyper-K) detector as a next generation underground water Cherenkov detector. It will serve far of long baseline neutrino oscillation experiment envisioned for upgraded J-PARC, and capable observing -- beyond sensitivity Super-Kamiokande (Super-K) proton decays, atmospheric neutrinos, neutrinos from astronomical origins. The design Hyper-K is based on highly successful Super-K, taking full advantage well-proven technology. (to be continued)
We present a search for non-zero theta_{13} and deviations of sin^2 theta_{23} from 0.5 in the oscillations atmospheric neutrino data Super-Kamiokande -I, -II, -III. No distortions flux consistent with are found both mass hierarchy hypotheses agreement data. The best fit at Delta m^2 = 2.1 x 10^-3 eV^2, 0.0, =0.5. In normal (inverted) constrained one-dimensional 90% C.L. to < 0.04 (0.09) 1.9 (1.7) 2.6 (2.7) eV^2. mixing angle is within 0.407 <= 0.583
We observed, for the first time, solar neutrinos in 1.0-1.5 MeV energy range. measured rate of pep neutrino interactions Borexino to be [3.1+-0.6(stat)+-0.3(syst)] counts/(day x 100 ton) and provided a constraint on CNO interaction <7.9 (95% C.L.). The absence signal is disfavored at 99.97% C.L., while 98% C.L. This unprecedented sensitivity was achieved by adopting novel data analysis techniques rejection cosmogenic 11C, dominant background 1-2 region. Assuming MSW-LMA solution...
Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in detector addition to upward-going muons surrounding rock. Compared previous result, which used only, signal acceptances light (few−GeV/c2−200−GeV/c2) WIMPs are significantly increased. We fit 3903 days of SK data contribution annihilation found no...
A search for day-night variations in the solar neutrino flux resulting from oscillations has been carried out using 504 day sample of data obtained at Super-Kamiokande. The absence a significant variation set an absolute independent exclusion region two oscillation parameter space.
A measurement of the energy spectrum recoil electrons from solar neutrino scattering in Super-Kamiokande detector is presented. The results shown here were obtained 504 days data taken between 31 May 1996 and 25 March 1998. shape measured compared with expectation for ${}^{8}\mathrm{B}$ neutrinos. comparison takes into account both kinematic related effects process. spectral observation gives a ${\ensuremath{\chi}}^{2}$ 25.3 15 degrees freedom, corresponding to $4.6%$ confidence level.
We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs), with 1679.6 live days data from Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking an excess high energy muon neutrinos WIMP annihilations in Sun, core Earth, and Galactic Center, as compared to number expected atmospheric neutrino background. No statistically significant was seen. calculate flux limits various angular cones around each...