A5054550789- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Advanced X-ray Imaging Techniques
- Medical Imaging Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Electrostatic Discharge in Electronics
- Magnetic confinement fusion research
- Astrophysics and Cosmic Phenomena
- Nuclear reactor physics and engineering
High Energy Accelerator Research Organization
2016-2025
Institute of Particle and Nuclear Studies
2011-2024
Japan Proton Accelerator Research Complex
2014-2024
Kyushu University
2019-2024
Indian Institute of Technology Hyderabad
2024
The University of Tokyo
2013-2024
Augustana University
2016-2023
Abilene Christian University
2023
PHENIX laboratory
2016-2023
Banaras Hindu University
2010-2023
We review the present status of Standard Model calculation anomalous magnetic moment muon. This is performed in a perturbative expansion fine-structure constant $\alpha$ and broken down into pure QED, electroweak, hadronic contributions. The QED contribution by far largest has been evaluated up to including $\mathcal{O}(\alpha^5)$ with negligible numerical uncertainty. electroweak suppressed $(m_\mu/M_W)^2$ only shows at level seventh significant digit. It two loops known better than one...
The gamman-->K(+)K(-)n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed 1.54+/-0.01 GeV/c(2) with a width smaller than 25 MeV/c(2) Gaussian significance of 4.6sigma. strangeness quantum number (S) the is +1. It can be interpreted as molecular meson-baryon or alternatively an exotic five-quark state (uuddsmacr;) that decays into neutron. consistent lowest member antidecuplet baryons predicted chiral soliton model.
This paper introduces a new approach to measure the muon magnetic moment anomaly |$a_{\mu} = (g-2)/2$| and electric dipole (EDM) |$d_{\mu}$| at J-PARC facility. The goal of our experiment is |$a_{\mu}$| using an independent method with factor 10 lower momentum, 20 smaller diameter storage-ring solenoid compared previous ongoing |$g-2$| experiments unprecedented quality storage field. Additional significant differences from present experimental include 1000 transverse emittance beam...
Differential cross sections and photon beam asymmetries for the gamma p rightarrow K+ Lambda Sigma0 reactions have been measured in energy range from 1.5 GeV to 2.4 angular Theta_{cm} = 0 60 of scattering angle center mass system at SPring-8/LEPS facility. The both found be positive increase with energy. differential agree data by CLAS collaboration cosTheta_{cm}<0.9 within experimental uncertainties, but discrepancy SAPHIR K+Lambda reaction is large cosTheta_{cm}>0.9. In reaction,...
The photo-production of ϕ mesons from Li, C, Al, and Cu at forward angles has been measured Eγ=1.5–2.4GeV. number events for incoherent is found to have a target mass dependence A0.72±0.07 in the kinematical region |t|⩽0.6GeV2/c2. total cross section ϕ–nucleon interaction, σϕN, estimated as 35−11+17mb using A-dependence yield Glauber-type multiple scattering theory. This value much larger than σϕN free space, suggesting that properties might change nuclear medium.
The γd→K+K−pn reaction has been studied to search for the evidence of Θ+ by detecting K+K− pairs at forward angles. Fermi-motion-corrected nK+ invariant mass distribution shows a narrow peak 1.524±0.002+0.003 GeV/c2. statistical significance calculated from shape analysis is 5.1 σ, and differential cross section γn→K−Θ+ estimated be 12±2 nb/sr in photon energy range 2.0 2.4 GeV LEPS angular assuming isotropic production γn center-of-mass system. obtained results support existence Θ+.9...
Differential cross sections for γp→K+Λ(1405) and γp→K+Σ0(1385) reactions have been measured in the photon energy range from 1.5 to 2.4 GeV angular of 0.8<cos(Θ)<1.0 K+ scattering angle center-of-mass system. This data is first measurement Λ(1405) photoproduction section. The line shapes Σ+π− Σ−π+ decay modes were different with each other, indicating a strong interference isospin 0 1 terms Σπ amplitudes. ratios production Σ0(1385) two ranges: near threshold (1.5<Eγ<2.0 GeV) far it...
A search for $K^-pp$ bound state (the lightest kaonic nucleus) has been performed using the $\gamma d \rightarrow K^+ \pi^- \rm{X}$ reaction at E$_\gamma$=1.5-2.4 GeV LEPS/SPring-8. The differential cross section of $K^+ \pi^-$ photo-production off deuterium measured first time in this energy region, and a bump structure was searched inclusive missing mass spectrum. statistically significant not observed region from 2.22 to 2.36 GeV/$c^2$, upper limits production were determined be 0.1$-$0.7...
The Technical Design for the COMET Phase-I experiment is presented in this paper. an at J-PARC, Japan, which will search neutrinoless conversion of muons into electrons field aluminium nucleus ($\mu-e$ conversion, $\mu^- N \to e^- N$); a lepton flavor violating process. experimental sensitivity goal process $3.1\times10^{-15}$, or 90 % upper limit branching ratio $7\times 10^{-15}$, factor 100 improvement over existing limit. expected number background events 0.032. To achieve target and...
Abstract This study developed a new current-readout technique capable of handling measurements with high count rates reaching 1 Gcps. By directly capturing the output current photomultiplier as digitized waveform, we estimated event rates, overcoming limitations imposed by pulse pileup constraints and deadtimes. innovative method was applied to muon spin rotation/relaxation/resonance experiment at Japan Proton Accelerator Research Complex, demonstrating its expected performance. Furthermore,...
Beam polarization asymmetries for the p(gamma-->,K+)Lambda and p(gamma-->,K+)Sigma(0) reactions are measured first time E(gamma)=1.5-2.4 GeV 0.6<cos((theta(c.m.)(K+))<1.0 by using linearly polarized photons at Laser-Electron-Photon facility SPring-8 (LEPS). The observed positive gradually increase with rising photon energy. data not consistent theoretical predictions based on tree-level effective-Lagrangian approaches. Including new results in development of models is, therefore, crucial...
Photoproduction of a phi meson on protons was studied by means linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections t -|t|min do not increase smoothly as increases but show local maximum around 2.0 angular distributions demonstrate that mesons are photoproduced predominantly helicity-conserving processes, and is likely due unnatural-parity processes.
A search for the Θ+ in reaction γd→pK−K+n was completed using CLAS detector at Jefferson Lab. study of same reaction, published earlier, reported observation a narrow resonance. The present experiment, with more than 30 times integrated luminosity our earlier measurement, does not show any evidence pentaquark angle-integrated upper limit on production mass range 1.52–1.56 GeV/c2 γd→pK−Θ+ is 0.3 nb (95% C.L.). This depends assumptions made and angular distribution production. Using Λ(1520) as...
Emission of muonium (|$\mu ^+e^-$|) atoms from a laser-processed aerogel surface into vacuum was studied for the first time. Laser ablation used to create hole-like regions with diameter about 270 |$\mu $|m in triangular pattern hole separation range 300–500 $|m. The emission probability sample is at least eight times higher than uniform one.
A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It near-ideal two-body system for precision test bound-state theory fundamental symmetries. The MuSEUM collaboration performed new measurement the muonium ground-state hyperfine structure at J-PARC using high-intensity pulsed beam high-rate capable positron counter. resonance transition was successfully observed near-zero magnetic field, interval $ν_{\text{HFS}}$ = 4.463302(4) GHz obtained with relative...
As a new method to determine the resonance frequency, Rabi-oscillation spectroscopy has been developed. In contrast conventional which draws curve, fits time evolution of Rabi oscillation. By selecting optimized it is shown that precision twice as good with frequency sweep. Furthermore, data under different conditions can be treated in unified manner, allowing more efficient measurements for systems consisting limited number short-lived particles produced by accelerators such muons. We have...