Jun Nishimura
A5085412804- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Noncommutative and Quantum Gravity Theories
- Synthesis and Properties of Aromatic Compounds
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Radiation Therapy and Dosimetry
- Particle Detector Development and Performance
- Supramolecular Chemistry and Complexes
- Porphyrin and Phthalocyanine Chemistry
- Synthetic Organic Chemistry Methods
- Molecular Sensors and Ion Detection
- Fullerene Chemistry and Applications
- Photochromic and Fluorescence Chemistry
- Radical Photochemical Reactions
- Theoretical and Computational Physics
- Aerospace Engineering and Energy Systems
- Atomic and Subatomic Physics Research
- Organic Chemistry Cycloaddition Reactions
- High-Energy Particle Collisions Research
High Energy Accelerator Research Organization
2015-2025
The Graduate University for Advanced Studies, SOKENDAI
2015-2025
Nippon Soken (Japan)
2023-2025
Institute of Space and Astronautical Science
2014-2024
Japan Aerospace Exploration Agency
2012-2024
University of Milano-Bicocca
2024
Kyoto University
1966-2023
Shizuoka University
2014-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2023
University of Siena
2023
Lateral and angular distribution functions of the electron showers are derived analytically with without Landau approximation including ionization loss. Tables numerical results these presented, their applied to analysis high energy cosmic ray phenomena. Relations between present theories others discussed critically, it is shown that other can be regarded as special cases our theories.
Extended results on the cosmic-ray electron $+$ positron spectrum from 11 GeV to 4.8 TeV are presented based observations with Calorimetric Electron Telescope (CALET) International Space Station utilizing data up November 2017. The analysis uses full detector acceptance at high energies, approximately doubling statistics compared previous result. CALET is an all-calorimetric instrument a total thickness of 30 ${X}_{0}$ normal incidence and fine imaging capability, designed achieve large...
In this paper, we present the analysis and results of a direct measurement cosmic-ray proton spectrum with CALET instrument onboard International Space Station, including detailed assessment systematic uncertainties. The observation period used in is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved very wide energy range necessary carry out measurements 50 GeV 10 TeV covering, for first time space, single whole interval previously investigated most cases separate...
We report cosmic-ray proton and helium spectra in energy ranges of 1-120 GeV nucleon-1 1-54 nucleon-1, respectively, measured by a flight the Balloon-borne Experiment with Superconducting Spectrometer (BESS) 1998. The magnetic rigidity cosmic ray was reliably determined highly precise measurement circular track uniform solenoidal field 1 T. Those were within overall uncertainties ±5% for protons ±10% nuclei including statistical systematic errors.
The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS a recent solar-minimum period. We have detected for first time characteristic peak at 2 GeV originating from interactions with interstellar gas. is reproduced theoretical calculations, implying that propagation models are basically correct and different species undergo universal propagation. Future data still higher statistics will allow us to...
Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons helium nuclei energy ranges, 1–540 GeV 1–250 GeV/n, respectively, flux muons range 0.6–400 GeV/c.
We present the first Monte Carlo results for supersymmetric matrix quantum mechanics with 16 supercharges at finite temperature. The recently proposed nonlattice simulation enables us to include effects of fermionic matrices in a transparent and reliable manner. internal energy nicely interpolates weak coupling behavior obtained by high temperature expansion, strong predicted from dual black-hole geometry. Polyakov line asymptotes low characteristic deconfined theory, suggesting absence...
Evidence of nonthermal X-ray emission and TeV gamma rays from supernova remnants (SNRs) have strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High-energy lose energy via synchrotron inverse Compton processes during propagation Galaxy. Because these radiative losses, liberated SNRs at distances larger than ~1 kpc, or times older ~105 yr, cannot reach solar system. We investigated electron spectrum observed system using an analytical method...
We reconsider the matrix model formulation of type IIB superstring theory in (9+1)-dimensional space-time. Unlike previous proposal which Wick rotation was used to make well-defined, we regularize Lorentzian by introducing infrared cutoffs both spatial and temporal directions. Monte Carlo studies reveal that two can be removed large-N limit thus obtained has no parameters other than one scale parameter. Moreover, find three out nine directions start expand at some "critical time", after...
The complex Langevin method is a promising approach to the complex-action problem based on fictitious time evolution of complexified dynamical variables under influence Gaussian noise. Although it known have restricted range applicability, use gauge cooling made applicable various interesting cases including finite density QCD in certain parameter regions. In this paper, we revisit argument for justification method. particular, point out subtlety time-evolved observables, which play crucial...
First results of a cosmic-ray electron and positron spectrum from 10 GeV to 3 TeV is presented based upon observations with the CALET instrument on International Space Station starting in October, 2015. Nearly half million events are included analysis. an all-calorimetric total vertical thickness 30 ${X}_{0}$ fine imaging capability designed achieve large proton rejection excellent energy resolution well into region. The observed over can be fit single power law spectral index...
We perform a direct test of the gauge-gravity duality associated with system N D0-branes in type IIA superstring theory at finite temperature. Based on fact that higher derivative corrections to supergravity action start order alpha;{'3}, we derive internal energy expansion around infinite 't Hooft coupling up subleading term one unknown coefficient. The power is shown be nicely reproduced by Monte Carlo data obtained nonperturbatively gauge side but large effective (dimensionless) constant....
The complex Langevin method aims at performing path integral with a action numerically based on complexification of the original real dynamical variables. One poorly understood issues concerns occasional failure in presence logarithmic singularities action, which appear, for instance, from fermion determinant finite density QCD. We point out that should be attributed to breakdown relation between weight satisfies Fokker-Planck equation and probability distribution associated stochastic...
The energy spectrum of cosmic-ray antiprotons (¯p's) from 0.17 to 3.5 GeV has been measured using 7886 ¯p's detected by BESS-Polar II during a long-duration flight over Antarctica near solar minimum in December 2007 and January 2008. This shows good consistency with secondary ¯p calculations. Cosmologically primary have investigated comparing calculated spectra. data show no evidence the evaporation primordial black holes.Received 28 July...
The discovery of the fact that black holes radiate particles and eventually evaporate led Hawking to pose well-known information loss paradox. This paradox caused a long serious debate since it claims fundamental laws quantum mechanics may be violated. A possible cure appeared recently from superstring theory, consistent theory gravity: if holographic description hole based on gauge/gravity duality is correct, not lost remains valid. Here we test this computer at level gravity for first...
A precise measurement of the cosmic-ray proton spectrum with Calorimetric Electron Telescope (CALET) is presented in energy interval from 50 GeV to 60 TeV, and observation a softening above 10 TeV reported. The analysis based on data collected during ∼6.2 years smooth operations aboard International Space Station covers broader range respect previous flux by CALET, an increase available statistics factor ∼2.2. Above few hundred we confirm our progressive spectral hardening higher...
We present the results of a direct measurement cosmic-ray helium spectrum with CALET instrument in operation on International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). very wide dynamic range allowed for collection data over large energy interval, ∼40 GeV ∼250 TeV, first time single low Earth orbit. measured shows evidence deviation flux power law more than 8σ progressive spectral hardening few...
The energy spectra of cosmic-ray low-energy antiprotons ( $\overline{p}$'s) and protons $p$'s) have been measured by BESS in 1999 2000, during a period covering reversal at the solar magnetic field. Based on these measurements, sudden increase $\overline{p}/p$ flux ratio following field was observed, it generally agrees with drift model modulation.