A5101884633- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Quantum Chromodynamics and Particle Interactions
- Nuclear physics research studies
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- SAS software applications and methods
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- Atomic and Molecular Physics
- Scientific Research and Discoveries
- Radiation Therapy and Dosimetry
- Hormonal Regulation and Hypertension
Kavli Institute for the Physics and Mathematics of the Universe
2015-2024
The University of Tokyo
2015-2024
Institute for Cosmic Ray Research
2015-2024
Kobe University
2010-2024
Juntendo University Shizuoka Hospital
2024
University of Bern
2023
Albert Einstein College of Medicine
2023
Eötvös Loránd University
2023
Boston University
2013-2023
Duke University
2018-2023
The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) 1 and sin(2)2θ(13) 0, expected number such is 1.5±0.3(syst). Under this hypothesis, probability to observe six or more candidate 7×10(-3), equivalent 2.5σ significance. At 90% C.L., are consistent 0.03(0.04) < 0.28(0.34)...
The T2K experiment is a long baseline neutrino oscillation experiment. Its main goal to measure the last unknown lepton sector mixing angle θ13 by observing νe appearance in νμ beam. It also aims make precision measurement of known parameters, Δm232 and sin22θ23, via disappearance studies. Other goals include various cross-section measurements sterile searches. uses an intense proton beam generated J-PARC accelerator Tokai, Japan, composed beamline, near detector complex (ND280), far...
The T2K experiment has observed electron neutrino appearance in a muon beam produced 295 km from the Super-Kamiokande detector with peak energy of 0.6 GeV. A total 28 events were detected an distribution consistent signal, corresponding to significance 7.3σ when compared 4.92±0.55 expected background events. In Pontecorvo-Maki-Nakagawa-Sakata mixing model, signal depends on several parameters including three angles θ12, θ23, θ13, mass difference Δm232 and CP violating phase δCP. this...
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...
Measurements are reported of the proton and deuteron spin structure functions ${g}_{1}^{p}$ ${g}_{1}^{d}$ at beam energies 29.1, 16.2, 9.7 GeV, ${g}_{2}^{p}$ ${g}_{2}^{d}$ a energy 29.1 GeV. The integrals ${\ensuremath{\Gamma}}_{p}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{p}{(x,Q}^{2})dx$ ${\ensuremath{\Gamma}}_{d}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{d}{(x,Q}^{2})dx$ were evaluated fixed ${Q}^{2}=3(\mathrm{GeV}{/c)}^{2}$ using full data set to yield...
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 report on measurements of neutrino oscillation using data from the T2K long-baseline experiment collected between 2010 and 2013. In an analysis muon disappearance alone, we find following estimates 68% confidence intervals for two possible mass hierarchies: Normal Hierarchy: $\sin^2\theta_{23}=0.514^{+0.055}_{-0.056}$ $\Delta m^2_{32}=(2.51\pm0.10)\times 10^{-3}$ eV$^2$/c$^4$ Inverted $\sin^2\theta_{23}=0.511\pm0.055$ m^2_{13}=(2.48\pm0.10)\times The accounts multi-nucleon mechanisms in...
After important upgrades to the experiment, Super-Kamiokande collaboration returns measuring solar mixing angle and mass splitting $\mathrm{\ensuremath{\Delta}}\phantom{\rule{0}{0ex}}{m}_{12}^{2}$. By focusing on low-energy ${}^{8}B$ neutrinos, is able single out neutrinos that undergo flavor conversion only through vacuum oscillations. The results are currently most precise values for mass-difference parameters relevant neutrino
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...
We report on the first search for nuclear recoils from dark matter in form of weakly interacting massive particles (WIMPs) with XENONnT experiment, which is based a two-phase time projection chamber sensitive liquid xenon mass 5.9 ton. During (1.09±0.03) ton yr exposure used this search, intrinsic ^{85}Kr and ^{222}Rn concentrations target are reduced to unprecedentedly low levels, giving an electronic recoil background rate (15.8±1.3) events/ton keV region interest. A blind analysis events...
Hyper-Kamiokande will be a next-generation underground water Cherenkov detector with total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that Super-Kamiokande. One the main goals is study |$CP$| asymmetry in lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, physics potential long-baseline experiment beam from J-PARC proton synchrotron presented. The analysis uses framework systematic uncertainties derived ongoing...
An analysis of atmospheric neutrino data from all four run periods \superk optimized for sensitivity to the mass hierarchy is presented. Confidence intervals $\Delta m^2_{32}$, $\sin^2 \theta_{23}$, \theta_{13}$ and $\delta_{CP}$ are presented normal inverted hypotheses based on alone. Additional constraints reactor $\theta_{13}$ published binned T2K muon disappearance electron appearance added fit give enhanced above parameters. Over range parameters allowed at 90% confidence level, favored...
The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an off-axis muon beam with a peak energy of about 0.6 GeV that originates at the J-PARC accelerator facility. Interactions neutrinos are observed near detectors placed 280 m from production target and far detector -- Super-Kamiokande (SK) located 295 km away. flux prediction is essential part successful interaction rates T2K important input to oscillation cross section measurements. A FLUKA GEANT3 based simulation...
The T2K experiment measures muon neutrino disappearance and electron appearance in accelerator-produced antineutrino beams. With an exposure of 14.7(7.6)×1020 protons on target the (antineutrino) mode, 89 νe candidates seven anti-νe are observed, while 67.5 9.0 expected for δCP=0 normal mass ordering. obtained 2σ confidence interval CP-violating phase, δCP, does not include CP-conserving cases (δCP=0, π). best-fit values other parameters sin2θ23=0.526+0.032−0.036 Δm232=2.463+0.071−0.070×10−3...
New data from the T2K neutrino oscillation experiment produce most precise measurement of mixing parameter ${\ensuremath{\theta}}_{23}$. Using an off-axis beam with a peak energy 0.6 GeV and set corresponding to $6.57\ifmmode\times\else\texttimes\fi{}1{0}^{20}$ protons on target, has fit energy-dependent ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ probability determine parameters. The 68% confidence limit ${\mathrm{sin}}^{2}({\ensuremath{\theta}}_{23})$ is...
We report on a blinded analysis of low-energy electronic-recoil data from the first science run XENONnT dark matter experiment. Novel subsystems and increased 5.9 tonne liquid xenon target reduced background in (1, 30) keV search region to $(15.8 \pm 1.3)$ events/(tonne$\times$year$\times$keV), lowest ever achieved detector $\sim$5 times lower than XENON1T. With an exposure 1.16 tonne-years, we observe no excess above set stringent new limits solar axions, enhanced neutrino magnetic moment,...
We have searched for proton decay via $p \rightarrow e^{+} \pi^{0}$ and \mu^{+} using Super-Kamiokande data from April 1996 to March 2015, 0.306 megaton$\cdot$years exposure in total. The atmospheric neutrino background rate IV is reduced almost half that of phase I-III by tagging neutrons associated with interactions. reach the lifetime further enhanced introducing new signal criteria select a hydrogen atom. No candidates were seen search. Two passed all selection been observed, but these...
Hyper-Kamiokande consists of two identical water-Cherenkov detectors total 520~kt with the first one in Japan at 295~km from J-PARC neutrino beam 2.5$^{\textrm{o}}$ Off-Axis Angles (OAAs), and second possibly Korea a later stage. Having detector would benefit almost all areas oscillation physics mainly due to longer baselines. There are several candidate sites baselines 1,000$\sim$1,300~km OAAs 1$^{\textrm{o}}$$\sim$3$^{\textrm{o}}$. We conducted sensitivity studies on for detector, either...
The T2K experiment reports updated measurements of neutrino and antineutrino oscillations using both appearance disappearance channels. This result comes from an exposure $14.9(16.4)\ifmmode\times\else\texttimes\fi{}1{0}^{20}$ protons on target in (antineutrino) mode. Significant improvements have been made to the interaction model far detector reconstruction. An extensive set simulated data studies also performed quantify effect uncertainties oscillation parameter sensitivity. performs...
The nature of dark matter and properties neutrinos are among the most pressing issues in contemporary particle physics. dual-phase xenon time-projection chamber is leading technology to cover available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity many alternative candidates. These detectors can also study through neutrinoless double-beta decay a variety astrophysical sources. A next-generation xenon-based detector will therefore be...
Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events in XENON1T experiment. Characterization intensity delayed electron backgrounds shows that resulting are correlated, position, with high-energy can effectively be vetoed. In this work we extend previous S2-only analyses down a single electron. From analysis, after removing correlated backgrounds,...
The T2K experiment presents new measurements of neutrino oscillation parameters using $19.7(16.3)\times10^{20}$ protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to previous analysis, an additional $4.7\times10^{20}$ POT data was collected FD. Significant improvements were made analysis methodology, with near-detector introducing selections and more than double data. Additionally, this is first use NA61/SHINE a replica tune flux model, interaction model...