K. Ishidoshiro
A5009119609- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Geophysics and Gravity Measurements
- Superconducting and THz Device Technology
- Particle Detector Development and Performance
- Geophysics and Sensor Technology
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Radiation Detection and Scintillator Technologies
- Advanced Frequency and Time Standards
- Astronomical Observations and Instrumentation
- Computational Physics and Python Applications
- Physics of Superconductivity and Magnetism
- Nuclear Physics and Applications
- Nuclear physics research studies
- Geomagnetism and Paleomagnetism Studies
- Scientific Research and Discoveries
- Seismic Waves and Analysis
- Cold Atom Physics and Bose-Einstein Condensates
Tohoku University
2015-2024
National Institute of Advanced Industrial Science and Technology
2024
High Energy Accelerator Research Organization
2011-2023
International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles
2023
The University of Tokyo
2006-2017
University of North Carolina at Chapel Hill
2016
Tohoku University Hospital
2014
Institute of Particle and Nuclear Studies
2012
Bunkyo University
2008
Tokyo University of Science
2006
We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification xenon-loaded liquid scintillator, we achieved a significant reduction ^{110m}Ag contaminant identified previous searches. Combining results from first and second phase, obtain lower limit 0νββ half-life T_{1/2}^{0ν}>1.07×10^{26} yr at 90% C.L., almost sixfold improvement over limits. Using commonly adopted nuclear matrix element calculations, corresponding...
The objectives of the DECi-hertz Interferometer Gravitational Wave Observatory (DECIGO) are to open a new window observation for gravitational wave astronomy and obtain insight into significant areas science, such as verifying characterizing inflation, determining thermal history universe, dark energy, describing formation mechanism supermassive black holes in center galaxies, testing alternative theories gravity, seeking hole matter, understanding physics neutron stars searching planets...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational antenna. It aims at detecting various kinds of waves between 1 mHz and 100 Hz frequently enough to open a new window observation for astronomy. The pre-conceptual design DECIGO consists three drag-free satellites, 1000 km apart from each other, whose relative displacements are measured by Fabry–Perot Michelson interferometer. We plan launch in 2024 after long intense development...
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...
DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational antenna, aiming to detect waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz 10 thus open a new window for astronomy universe. will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by differential Fabry-Perot interferometer, four units triangular...
The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search upgraded detector with almost double amount of xenon and ultralow radioactivity container, corresponding to exposure 970 kg yr ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation xenon, have required use novel background rejection...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational antenna. DECIGO expected to open a new window of observation for astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries universe such as dark energy, formation mechanism supermassive black holes, inflation universe. The pre-conceptual design consists three drag-free spacecraft, whose relative displacements are measured by differential Fabry-Perot Michelson...
Abstract The next core-collapse supernova in the Milky Way or its satellites will represent a once-in-a-generation opportunity to obtain detailed information about explosion of star and provide significant scientific insight for variety fields because extreme conditions found within. Supernovae our galaxy are not only rare on human timescale but also happen at unscheduled times, so it is crucial be ready use all available instruments capture possible from event. first indication potential...
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)...
We present a precision analysis of the $^{136}$Xe two-neutrino $\beta\beta$ electron spectrum above 0.8 MeV, based on high-statistics data obtained with KamLAND-Zen experiment. An improved formalism for rate allows us to measure ratio leading and subleading $2\nu\beta\beta$ nuclear matrix elements (NMEs), $\xi^{2\nu}_{31} = -0.26^{+0.31}_{-0.25}$. Theoretical predictions from shell model majority quasiparticle random-phase approximation (QRPA) calculations are consistent experimental limit....
We report on a search for electron antineutrinos ($\bar{\nu}_e$) from astrophysical sources in the neutrino energy range 8.3 to 30.8 MeV with KamLAND detector. In an exposure of 6.72 kton-year liquid scintillator, we observe 18 candidate events via inverse beta decay reaction. Although there is large background uncertainty neutral current atmospheric interactions, find no significant excess over model predictions. Assuming several supernova relic spectra, give upper flux limits 60--110...
The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95GHz. 43-GHz results have been published in QUIET Collaboration et al. (2011), here we report measurement of CMB polarization power spectra using 95-GHz data. This data set comprises 5337 hours observations recorded by an array 84 polarized coherent receivers with a total sensitivity 87 uK sqrt(s). Four low-foreground fields were observed, covering ~1000 square degrees effective angular...
We propose a novel type of gravitational-wave antenna, formed by two bar-shaped test masses and laser-interferometric sensors to monitor their differential angular fluctuations. This antenna has fundamental sensitivity low-frequency signals below 1 Hz, even with ground-based configuration. In addition, it is possible expand the observation band lower limit determined time, using modulation up-conversion rotation antenna. The potential this superior those current detectors in mHz-10 Hz...
LiteBIRD [Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection] is a small to map microwave (CMB) radiation over full sky at large angular scales with unprecedented precision. Cosmological inflation, which leading hypothesis resolve problems in Big Bang theory, predicts that primordial gravitational waves were created during inflationary era. Measurements CMB are known as best probe detect waves. The working group authorized...
The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting imprint of inflationary gravitational waves at large angular scales (~ 1 degree). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. polarimeters which form focal planes use highly compact design based High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational antenna. The goal of DECIGO to detect waves from various kinds sources mainly between 0.1 Hz and 10 thus open a new window observation for astronomy. will consist three drag-free spacecraft, 1000 km apart each other, whose relative displacements are measured by Fabry—Perot Michelson interferometer. We plan launch pathfinder first demonstrate technologies required realize and, if...
We present a search for neutrinoless double-beta ($0\nu\beta\beta$) decay of $^{136}$Xe using the full KamLAND-Zen 800 dataset with 745 kg enriched xenon, corresponding to an exposure $2.097$ ton yr $^{136}$Xe. This updated benefits from more than twofold increase in exposure, recovery photo-sensor gain, and reduced background muon-induced spallation xenon. Combining previous phase, we obtain lower limit $0\nu\beta\beta$ half-life $T_{1/2}^{0\nu} > 3.8 \times 10^{26}$ at 90% C.L., factor 1.7...
A space gravitational-wave antenna, DECIGO (DECI-hertz interferometer Gravitational wave Observatory), will provide fruitful insights into the universe, particularly on formation mechanism of supermassive black holes, dark energy and inflation universe. In current pre-conceptual design, be comprising four units; each unit formed by three drag-free spacecraft with 1000 km separation. Since an extremely challenging mission high-precision flight long baseline, it is important to increase...
Abstract This paper is a sequel to our 2015 paper, Kato et al., which calculated the luminosities and spectra of electron-type anti-neutrinos ( <?CDATA ${\bar{\nu }}_{e}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mi>ν</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>e</mml:mi> </mml:msub> </mml:math> ) from progenitors core-collapse supernovae. Expecting that capability detect neutrinos ${\nu...
Aiming to distinguish two types of progenitors core-collapse supernovae, i.e., one with a core composed mainly oxygen and neon (abbreviated as ONe core) the other an iron (or Fe core), we calculated luminosities spectra neutrinos emitted from these cores prior gravitational collapse, taking neutrino oscillation into account. We found that total energies are , which is much smaller than for cores. The average energy, on hand, twice large those produced by plasmon decays in more numerous...
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...