A5012989844- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Muon and positron interactions and applications
- Dark Matter and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Superconducting Materials and Applications
- Atmospheric Ozone and Climate
- Advanced Decision-Making Techniques
- Pulsars and Gravitational Waves Research
- Electrical Fault Detection and Protection
- Quality and Safety in Healthcare
- Superconducting and THz Device Technology
- Magnetic confinement fusion research
- Solar and Space Plasma Dynamics
- Advanced Sensor and Control Systems
- Galaxies: Formation, Evolution, Phenomena
- Electronic Health Records Systems
Kavli Institute for the Physics and Mathematics of the Universe
2024
The University of Tokyo
2021-2024
Institute for Cosmic Ray Research
2024
Imperial College London
2011-2024
University of Toyama
2024
Nagoya University
2024
University of Bern
2023
Albert Einstein College of Medicine
2023
Eötvös Loránd University
2023
Boston University
2013-2023
A new search for the diffuse supernova neutrino background (DSNB) flux has been conducted at Super-Kamiokande (SK), with a $22.5\times2970$-kton$\cdot$day exposure from its fourth operational phase IV. The analysis improves on existing reduction techniques and systematic uncertainties takes advantage of an improved neutron tagging algorithm to lower energy threshold compared previous phases SK. This allows setting world's most stringent upper limit extraterrestrial $\bar{\nu}_e$ flux,...
We report the first search result for flux of astrophysical electron antineutrinos energies O(10) MeV in gadolinium-loaded Super-Kamiokande (SK) detector. In June 2020, gadolinium was introduced to ultra-pure water SK detector order detect neutrons more efficiently. this new experimental phase, SK-Gd, we can via inverse beta decay with efficient background rejection and higher signal efficiency thanks high neutron tagging technique. paper, initial stage SK-Gd a $22.5\times552$ $\rm kton\cdot...
We report a search for cosmic-ray boosted dark matter with protons using the 0.37 megaton×years data collected at Super-Kamiokande experiment during 1996-2018 period (SKI-IV phase). searched an excess of proton recoils above atmospheric neutrino background from vicinity Galactic Center. No such is observed, and limits are calculated two reference models either constant interaction cross section or through scalar mediator. This first experimental hadrons directional information. The results...
We present a measurement of neutrino oscillation parameters with the Super-Kamiokande detector using atmospheric neutrinos from complete pure-water SK I–V (April 1996–July 2020) dataset, including events an expanded fiducial volume. The dataset corresponds to 6511.3 live days and exposure 484.2 kiloton-years. Measurements <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi...
The first loading of gadolinium (Gd) into Super-Kamiokande in 2020 was successful, and the neutron capture efficiency on Gd reached 50%. To further increase to 75%, 26.1 tons Gd2(SO4)3⋅8H2O additionally loaded (SK) from May 31 July 4, 2022. As amount doubled compared loading, capacity powder dissolving system doubled. We also developed new batches sulfate with even reduced radioactive impurities. In addition, a more efficient screening method devised implemented evaluate these...
The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and Super-Kamiokande detector. Special emphasis is placed on measuring mixing angle theta_13 by observing electron appearance via sub-dominant to oscillation, searching for CP violation in lepton sector. includes a sophisticated, off-axis, near detector, ND280, situated 280 m downstream production target order measure properties understand better interactions at energy scale below...
We searched for proton decay via $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{K}^{0}$ in $0.37\text{ }\text{ }\mathrm{Mton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ of data collected between 1996 and 2018 from the Super-Kamiokande water Cherenkov experiment. The selection criteria were defined separately ${K}_{S}^{0}$ ${K}_{L}^{0}$ channels. No significant event excess has been observed. As a result this analysis, which extends previous search by an additional $0.2\text{...
We report the first measurement of atmospheric neutrino-oxygen neutral-current quasielastic (NCQE) cross section in gadolinium-loaded Super-Kamiokande (SK) water Cherenkov detector. In June 2020, SK began a new experimental phase, named SK-Gd, by loading 0.011% mass gadolinium into ultrapure The introduction to has effect improving neutron-tagging efficiency. Using 552.2 day dataset from August 2020 2022, we measure NCQE be <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...
As long-baseline neutrino experiments enter the precision era, difficulties associated with understanding interaction cross sections on atomic nuclei are expected to limit experimental sensitivities oscillation parameters. In particular, ability relate observables energy in previous has relied solely theoretical models of neutrino-nucleus interactions, which currently suffer from very large uncertainties. By observing charged current $ν_μ$ interactions over a continuous range off-axis angles...
Among multi-messenger observations of the next galactic core-collapse supernova, Super-Kamiokande (SK) plays a critical role in detecting emitted supernova neutrinos, determining direction to (SN), and notifying astronomical community these advance optical signal. On 2022, SK has increased gadolinium dissolved its water target (SK-Gd) achieved Gd concentration 0.033%, resulting enhanced neutron detection capability, which turn enables more accurate determination direction. Accordingly,...
Abstract Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernovae continuously, in real time, since the start operations 1996. The present work focuses on detecting more distant whose event rate may be too small to trigger but identified using an offline approach. analysis data collected from 2008 2018 found no evidence bursts. This establishes upper limit 0.29 yr −1 out 100 kpc at 90% C.L. For that fail explode and collapse directly black holes...
Cosmic-ray muons that enter the Super-Kamiokande detector cause hadronic showers due to spallation in water, producing neutrons and radioactive isotopes. These are a major background source for studies of MeV-scale neutrinos searches rare events. In 2020, gadolinium was introduced into ultra-pure water improve detection efficiency neutrons. this study, cosmogenic neutron yield measured using data acquired during period after loading. The found be...
The Super-Kamiokande and T2K collaborations present a joint measurement of neutrino oscillation parameters from their atmospheric beam data. It uses common interaction model for events overlapping in energy correlated detector systematic uncertainties between the two datasets, which are found to be compatible. Using 3244.4 days data exposure $19.7(16.3) \times 10^{20}$ protons on target (anti)neutrino mode, analysis finds 1.9$\sigma$ exclusion CP-conservation (defined as $J_{CP}=0$)...
Radioactivity induced by cosmic muon spallation is a dominant source of backgrounds for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi mathvariant="script">O</a:mi><a:mo stretchy="false">(</a:mo><a:mn>10</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>MeV</a:mi><a:mo stretchy="false">)</a:mo></a:mrow></a:math> neutrino interactions in water Cherenkov detectors. In particular, it crucial to reduce measure the solar spectrum and find from distant...
Abstract In 2020, the Super-Kamiokande (SK) experiment moved to a new stage (SK-Gd) in which gadolinium (Gd) sulfate octahydrate was added water detector, enhancing efficiency detect thermal neutrons and consequently improving sensitivity low energy electron anti-neutrinos from inverse beta decay (IBD) interactions. SK-Gd has potential provide early alerts of incipient core-collapse supernovae through detection nuclear processes responsible for cooling massive stars before gravitational...
We present a measurement of neutrino oscillation parameters with the Super-Kamiokande detector using atmospheric neutrinos from complete pure-water SK I-V (April 1996-July 2020) data set, including events an expanded fiducial volume. The set corresponds to 6511.3 live days and exposure 484.2 kiloton-years. Measurements $\Delta m^2_{32}$, $\sin^2\theta_{23}$, $\sin^2 \theta_{13}$, $\delta_{CP}$, preference for mass ordering are presented alone, constraints on \theta_{13}$ reactor experiments....
Radioactivity induced by cosmic muon spallation is a dominant source of backgrounds for $\mathcal{O}(10)~$MeV neutrino interactions in water Cherenkov detectors. In particular, it crucial to reduce measure the solar spectrum and find from distant supernovae. this paper we introduce new techniques locate muon-induced hadronic showers efficiently reject backgrounds. Applying these analysis with an exposure $2790\times22.5$~kton.day increases signal efficiency $12.6\%$, approximately...
Electrical safety - Where were we yesterday? are today? will be in the future? The culture is continuing to evolve provide a safer work environment for people working around electrical equipment. To improve safety, it takes commitment continuous improvement of culture. New thoughts and ideas critical. This paper addresses how practices have changed over time recommends upgrade existing change new need developed cause higher performance all exposed hazards.
Recent neutrino oscillation results have shown that the existing long baseline experiments some sensitivity to effects of CP violation in sector. This is currently statistically limited, but next generation experiments, DUNE and Hyper-K, will provide an order magnitude more events. To reach full potential these datasets we must achieve a commensurate improvement our understanding systematic uncertainties beset them. talk describes two proposed intermediate detectors for current future Japan,...