A5003388103- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Geophysics and Sensor Technology
- Cosmology and Gravitation Theories
- Seismic Waves and Analysis
- High-pressure geophysics and materials
- Computational Physics and Python Applications
- Solar and Space Plasma Dynamics
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
The University of Tokyo
2015-2024
Kavli Institute for the Physics and Mathematics of the Universe
2010-2024
Science Council of Japan
2017-2021
National Astronomical Observatory of Japan
2020
Institute of Space and Astronautical Science
2017-2019
Aomori University
2017-2019
Aligarh Muslim University
2019
Shibaura Institute of Technology
2019
Institute for Cosmic Ray Research
2001-2018
Waseda University
2017
A neutrino burst was observed in the Kamiokande II detector on 23 February, 7:35:35 UT (\ifmmode\pm\else\textpm\fi{}1 min) during a time interval of 13 sec. The signal consisted 11 electron events energy 7.5 to 36 MeV, which first two point back Large Magellanic Cloud with angles 18\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}18\ifmmode^\circ\else\textdegree\fi{} and 15\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}27\ifmmode^\circ\else\textdegree\fi{}.
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....
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...
A data sample of 1040 days from the Kamiokande II detector, consisting subsamples 450 at electron-energy threshold Ee≥9.3 MeV and 590 Ee≥7.5 MeV, yields a clear directional correlation solar-neutrino-induced electron events with respect to Sun measurement differential distribution. These provide unequivocal evidence for production B8 by fusion in Sun. The measured flux solar neutrinos two relative prediction standard model is 0.46±0.05(stat)±0.06(syst). total tested short-term time...
The properties of the Kamiokande-II detector and method measurement are described in detail. data on neutrino burst from supernova SN1987A 23 February 1987 at 7:35:35 UT\ifmmode\pm\else\textpm\fi{}1 min presented, with records earlier later observation periods which other events possibly associated might have occurred. There is no evidence for any excess neutrino-induced events, either a few seconds duration or over longer time interval, relative to usual count rate, excepting only UT....
We extend our calculation of the atmospheric neutrino fluxes to polar and tropical regions. It is well known that air density profiles in regions are different from mid-latitude region. Also there large seasonal variations In this extension, we use NRLMSISE-00 global model J. M. Picone, Geophys. Res. 107, SIA 15 (2002), replacing U.S.-standard 1976 model, which has no positional or variations. With study flux at with The geomagnetic international reference field (IGRF) have used calculations...
Received 6 October 2015DOI:https://doi.org/10.1103/RevModPhys.88.030501© 2016 Nobel Foundation, Published by The American Physical Society*The 2015 Prize for Physics was shared Takaaki Kajita and Arthur B. McDonald. These papers are the text of address given in conjunction with award.Physics Subject Headings (PhySH)Research AreasSolar neutrinosGravitation, Cosmology & Astrophysics
Atmospheric neutrino-fluxes are calculated over the wide energy range from 30 MeV to 3,000 GeV for study of neutrino-physics using data underground neutrino-detectors. The atmospheric muon-flux at high altitude and sea level is studied calibrate low energies respectively. agreement our calculation with observations satisfactory. uncertainty also studied.
The method of $^{8}\mathrm{B}$ solar-neutrino measurement by means the reaction ${\ensuremath{\nu}}_{e}e\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}e$ in Kamiokande II detector is described detail. A data sample 1040 live days time period January 1987 through April 1990 yields a clear directional correlation solar-neutrino-induced electron events with respect to Sun and differential energy distribution. measured flux solar neutrinos from subsamples 450 at threshold...
We have revised the calculation of flux atmospheric neutrinos based on a three-dimensional scheme with realistic IGRF geomagnetic model. The primary model has been revised, AMS and BESS observations, interaction updated to DPMJET-III. With fast simulation code computer system, statistical errors in Monte Carlo study are negligible. estimate total uncertainty neutrino prediction is reduced $\ensuremath{\lesssim}10%$ below 10 GeV. ``three-dimensional effects'' found be almost same as dipole...
We present the calculation of atmospheric neutrino fluxes with an interaction model named JAM, which is used in PHITS (Particle and Heavy-Ion Transport code System) [K. Niita et al., Radiation Measurements 41, 1080 (2006).]. The JAM agrees HARP experiment [H. Collaboration, Astropart. Phys. 30, 124 (2008).] a little better than DPMJET-III [S. Roesler, R. Engel, J. Ranft, arXiv:hep-ph/0012252.]. After some modifications, it reproduces muon flux below $1\text{ }\text{ }\mathrm{GeV}/c$ at...
We explore the possibility of simultaneous determination neutrino mass hierarchy and CP violating phase by using two identical detectors placed at different baseline distances. focus on a possible experimental setup beam from J-PARC facility in Japan with power 4MW megaton (Mton)-class water Cherenkov detectors, one Kamioka other somewhere Korea. demonstrate, under reasonable assumptions systematic uncertainties, that two-detector complex each fiducial volume 0.27 Mton has potential...
An analysis of the Mikheyev-Smirnov-Wolfenstein effect using 1040 days Kamiokande-II data is reported, which provides constraints on neutrino-oscillation parameters. The measured recoil-electron energy spectrum alone leads to conclusion that adiabatic region, 7.2\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$${\mathrm{sin}}^{2}$2\ensuremath{\theta}6.3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}3}$,...
Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei the atmosphere. Electron and muon mainly by chain charged pions to muons electrons. have been observed large underground detectors. Depending on their energy, these fully contained events, partially or upward going events. The energy range covered events is a few hundred MeV above 100 GeV. It has known for about ten years that some data suggested existence neutrino...
Searches for possible day-night and semiannual variations of the $^{8}\mathrm{B}$ solar neutrino flux are reported based on 1040 days Kamiokande-II data. Within statistical error, no such short-time were observed. The limit difference sets a constraint neutrino-oscillation parameters. A region defined by ${\mathrm{sin}}^{2}$2\ensuremath{\theta}>0.02...
Major construction and initial-phase operation of a second-generation gravitational-wave detector KAGRA has been completed. The entire 3-km is installed underground in mine order to be isolated from background seismic vibrations on the surface. This allows us achieve good sensitivity at low frequencies high stability detector. Bare-bones equipment for interferometer first test run was accomplished March April 2016 with rather simple configuration. initial configuration named {\it iKAGRA}. In...
Abstract KAGRA is a newly build gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this paper, one of series articles featuring KAGRA, we discuss the science targets projects, considering not only baseline (current design) but also its future upgrade candidates (KAGRA+) for near to middle term ($\sim$5 years).
KAGRA is a gravitational-wave (GW) detector constructed in Japan with two unique key features: It was underground, and the test-mass mirrors are cooled to cryogenic temperatures. These features not included other kilometer-scale detectors but will be adopted future such as Einstein Telescope. performed its first joint observation run GEO600 2020. In this observation, sensitivity of GWs inferior that LIGO Virgo. However, further upgrades ongoing reach for detecting next run, which scheduled...