Yuichi Toyama
A5046171124- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Cardiac electrophysiology and arrhythmias
- Cardiac Arrhythmias and Treatments
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- High-Energy Particle Collisions Research
- Cardiac pacing and defibrillation studies
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Ion channel regulation and function
- Radiation Detection and Scintillator Technologies
- Particle accelerators and beam dynamics
- Dark Matter and Cosmic Phenomena
- Advanced X-ray Imaging Techniques
- Neuroscience and Neural Engineering
- Laser-induced spectroscopy and plasma
- X-ray Spectroscopy and Fluorescence Analysis
- Laser-Plasma Interactions and Diagnostics
- Cardiovascular Effects of Exercise
- Laser-Matter Interactions and Applications
- Autoimmune and Inflammatory Disorders
Chubu University
2022-2025
Tohoku University
2016-2024
Thomas Jefferson National Accelerator Facility
2023-2024
Hirosaki University
2018-2024
Johannes Gutenberg University Mainz
2022
Helmholtz Institute Mainz
2022
GSI Helmholtz Centre for Heavy Ion Research
2022
Jichi Medical University
2020-2022
University of Toyama
2018
Meteorological Research Institute
1960
In an emulsion-counter hybrid experiment performed at J-PARC, a $Ξ^-$ absorption event was observed which decayed into twin single-$Λ$ hypernuclei. Kinematic calculations enabled unique identification of the reaction process as $Ξ^{-} + ^{14}$N$\ \rightarrow\ ^{10}_Λ$Be $^5_Λ$He. For binding energy $Ξ^{-}$ hyperon in $Ξ^-$-$^{14}$N system value $1.27 \pm 0.21$ MeV deduced. The level is likely nuclear $1p$ state indicates weak $ΞN$-$ΛΛ$ coupling.
A double-$\Lambda$ hypernucleus, ${}_{\Lambda\Lambda}\mathrm{Be}$, was observed by the J-PARC E07 collaboration in nuclear emulsions tagged $(K^{-},K^{+})$ reaction. This event interpreted as a production and decay of $ {}_{\Lambda\Lambda}^{\;10}\mathrm{Be}$, ${}_{\Lambda\Lambda}^{\;11}\mathrm{Be}$, or ${}_{\Lambda\Lambda}^{\;12}\mathrm{Be}^{*}$ via $\Xi^{-}$ capture ${}^{16}\mathrm{O}$. By assuming atomic 3D state, binding energy two $\Lambda$ hyperons$\,$($B_{\Lambda\Lambda}$) these...
The x-ray spectroscopy of the muonic atom has attracted atomic, nuclear, and particle physicists since its discovery. properties a atom, such as binding energy or atomic radius, are different from an ordinary because difference in mass between muon electron. Our collaboration employed superconductor transition-edge sensor (TES) microcalorimeters for atom. Thanks to recent detector development, 44-keV lines Ar, which is important precision test bound-state quantum electrodynamics, 76-keV Si,...
We investigated the energy dependence of number triggered pixels, or cluster size, when charged particles are detected using TimePix3 detector with a silicon sensor. measured protons in range 1.5~3.3 MeV from Pelletron accelerator at RIKEN 500 um-thick determined experimental results size comprised between 30 and 80 pixels. To understand physical process that produces large images its dependence, we simulated charge carrier drifts sensor, assuming incidence proton detector. The sizes...
A mass spectroscopy experiment with a pair of nearly identical high-resolution spectrometers and tritium target was performed in Hall at Jefferson Lab. Utilizing the (e,e′K+) reaction, enhancements, which may correspond to possible Λnn resonance ΣNN states, were observed an energy resolution about 1.21 MeV (σ), although greater statistics are needed make definitive identifications. An experimentally measured state provide unique constraint determining Λn interaction, for no scattering data...
Interference free distribution and speciation analysis of uranium are achieved by using a transition-edge sensor for microbeam X-ray measurements in the hard region.
Although there are several diagnostic criteria for left ventricular hypertrophy (LVH), their sensitivity remains low. A recent study reported that the sum of amplitude deepest S wave in any lead (SD) and V4 (SV4) (SD + SV4) improved compared with commonly used criteria. To test whether this new formula improves Japanese general population, we analyzed 12-lead electrocardiograms residents participating Iwaki Health Promotion Project (n = 866). Left mass was calculated by echocardiography,...
The heart of the medaka, a small fish native to East Asia, has electrophysiological aspects similar mammalian hearts. We found that rates medaka were more humans than mice or rats. Medaka exhibited electrocardiogram patterns those humans, suggesting similarity in cardiac impulse formation and propagation. Their hearts also responsiveness verapamil, calcium channel antagonist; atropine, parasympathetic nerve blocker; propranolol, sympathetic β-adrenergic isoproterenol, agonist. successfully...
Background Although PAR‐1 (protease‐activated receptor‐1) exerts important functions in the pathophysiology of cardiovascular system, role PAR ‐1 signaling heart failure development remains largely unknown. We tested hypothesis that inhibition has protective effects on progression cardiac remodeling induced by chronic renin–angiotensin system activation using renin‐overexpressing hypertensive (Ren‐Tg) mice. Methods and Results treated 12‐ to 16‐week‐old male wild‐type ( WT ) mice Ren‐Tg with...
The electromagnetic form factors of the proton and neutron encode information on spatial structure their charge magnetization distributions. While measurements are relatively straightforward, lack a free target makes neutron’s more challenging sensitive to experimental or model-dependent uncertainties. Various experiments have attempted extract from scattering in deuterium, with different techniques providing different, sometimes large, systematic We present results novel measurement...
The small binding energy of the hypertrition leads to predictions non-existence bound hypernuclei for isotriplet three-body systems such as $nn\Lambda$. However, invariant mass spectroscopy at GSI has reported events that may be interpreted $nn\Lambda$ state. state was sought by missing-mass via $(e,e'K^+)$ reaction Jefferson Lab's experimental Hall A. present experiment higher sensitivity $nn\Lambda$-state investigation in terms better precision a factor about three. analysis shown this...
A high-precision hypernuclear experiment has been commissioned at the Mainz Microtron (MAMI) to determine hypertriton Λ binding energy via decay-pion spectroscopy. The method successfully pioneered with 4 H studies in last decade. makes use of a novel high luminosity lithium target length 45mm while being only 0.75mm thick keep momentum smearing decay pions low. target-to-beam alignment as well observation deposited heat is achieved newly developed thermal imaging system. Together precise...
BackgroundThe subcutaneous implantable cardioverter-defibrillator (S-ICD) is effective in preventing sudden cardiac death. Compared with transvenous ICDs, S-ICDs have a lower rate of inappropriate shocks (IASs) for supraventricular arrhythmias, but such T-wave oversensing (TWO) and extracardiac myopotentials are more common. No screening tests to identify patients at risk IAS due myopotential interference (MPI) currently available.ObjectiveThe purpose this study was assess the efficacy tube...
In 2018, the E12-17-003 experiment was conducted at Thomas Jefferson National Accelerator Facility (JLab) to explore possible existence of an nnLambda state in reconstructed missing mass distribution from a tritium gas target. As part this investigation, data also collected using gaseous hydrogen target, not only for precise absolute scale calibration but study Lambda/Sigma^0 electroproduction. This dataset acquired Q^2~0.5 (GeV/c)^2, W=2.14 GeV, and theta_{gamma K}^{c.m.}~8 deg. It covers...
A beam profile monitor (BPM) has been developed to measure photon beams at the BM4 beamline of Mikamine site, Research Center for Accelerator and Radioisotope Science (RARIS-Mikamine; previously known as ELPH) Tohoku University. The BPM comprises plastic scintillation fibers SiPMs, enabling high-precision, real-time measurements in 1 GeV region. Data acquisition utilized streaming TDC, a firmware commonly employed J-PARC Hadron-hall, detection high-intensity with count rates reaching several...
Electronic $K$ x rays emitted by muonic Ar atoms in the gas phase were observed using a superconducting transition-edge-sensor microcalorimeter. The high-precision energy spectra provided clear signature of presence accompanied few electrons, which have never been before. One-, two-, and three-electron bound, i.e., H-like, He-like, Li-like, identified from electronic hyper-satellite rays. These are after charge transfer process collisions with surrounding atoms. With aid theoretical...