A5061470866- Particle accelerators and beam dynamics
- Muon and positron interactions and applications
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Gyrotron and Vacuum Electronics Research
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Neutrino Physics Research
- High-Energy Particle Collisions Research
- Plasma Diagnostics and Applications
- Quantum Chromodynamics and Particle Interactions
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Advanced Chemical Physics Studies
- Nuclear physics research studies
- Esophageal and GI Pathology
- Cold Atom Physics and Bose-Einstein Condensates
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Quantum Electrodynamics and Casimir Effect
- Radiation Detection and Scintillator Technologies
- Electrostatic Discharge in Electronics
Japan Proton Accelerator Research Complex
2018-2024
High Energy Accelerator Research Organization
2000-2024
National Cancer Center Hospital East
2022-2024
The Graduate University for Advanced Studies, SOKENDAI
2021
The University of Tokyo
2010-2020
Nidek (Japan)
2019
Institute of Particle Physics
2017
RIKEN Nishina Center
2009-2011
Tokyo University of Science
1981-2010
Ludwig-Maximilians-Universität München
2010
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...
We report the first direct measurement of hyperfine transition ground state positronium. The structure between ortho-positronium and para-positronium is about 203 GHz. develop a new optical system to accumulate 10 kW power using gyrotron, mode converter, Fabry-P\'erot cavity. has been observed with significance 5.4 standard deviations. probability measured be $A={3.1}_{\ensuremath{-}1.2}^{+1.6}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\text{ }\text{...
At the J-PARC Muon Science Facility (MUSE), MuSEUM collaboration is now performing new precision measurements of ground state hyperfine structure (HFS) both muonium and muonic helium atoms. High-precision ground-state HFS are recognized as one most sensitive tools for testing bound-state quantum electrodynamics theory to precisely probe standard model determine fundamental constants positive muon magnetic moment mass. The same technique can also be employed measure HFS, obtain negative mass,...
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...
CP violation in the quark sector has been well established over last decade, but not observed lepton sector. We search for violating decay processes positronium, using angular correlation of (S x k{1})(S k{1}x k{2}), where S is positronium spin and k{1}, k{2} are directions photons. To a sensitivity 2.2x10{-3}, no found, which at level amplitude K meson. A 90% confidence interval parameter (C{CP}) was determined to be -0.0023<C{CP}<0.0049. This result factor 7 more strict than that previous...
We report on the first measurement of Breit–Wigner resonance transition from ortho-positronium to para-positronium. have developed an optical system accumulate a power over 20 kW using frequency-tunable gyrotron and Fabry–Pérot cavity. This opens new era millimeter-wave spectroscopy, enables us directly determine both hyperfine interval decay width para-Ps.
Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and QED predictions. This may be due to contribution unknown new physics or common systematic effects previous measurements, all which Zeeman effect was used. We propose method directly measure Ps-HFS using high power gyrotron. compare two resonators have developed supply sufficient...
A proposed new method of cooling positronium is to realize the Bose–Einstein condensation (BEC) positronium. We perform detailed studies three processes: (1) thermalization processes between and silica walls a cavity, (2) Ps–Ps scattering (3) laser cooling. The process shown be not sufficient for BEC. collision have big effect on performance. combine both methods establish an efficient also propose optical system
A nonlinear interaction between photons is observed in a process that involves charge sources. To observe this vacuum, there are growing number of theoretical and experimental studies. This may contain exotic contribution from new physics beyond the Standard Model particle physics, probed by experiments using high-power laser or high-field magnet, more recently an X-ray Free-Electron Laser (XFEL). Here, we review present status our testing various vacuum processes. We describe four with...
Power upgrades of accelerators and the development new beamlines have prompted high-precision measurements to be updated reveal phenomena. Several operate in mega-watt regime, a number experiments are planned for future, search evidence physics beyond standard model by investigating events relevant secondary particles. will constructed based on concepts high-power proton drivers, i.e., meson factories. These transport particles, namely muons, with higher efficiency than conventional...
We report a search for photon-photon elastic scattering in vacuum the X-ray region at an energy center of mass system \omega_{cms} =6.5 keV which QED cross section is \sigma_{QED} =2.5 \times 10^{-47} m^2. An beam provided by SACLA Free Electron Laser split and two beamlets are made to collide right angle, with total integrated luminosity (1.24 \pm 0.08) 10^{28} m^{-2}. No signal X rays from that satisfy correlation between angle were detected. obtain 95% C.L. upper limit 1.9 10^{-27} m^2...
Positronium is an ideal system for research on QED, especially in a bound state. A discrepancy (3.9σ) found recently between measured HFS values and the QED prediction (including up-to O(α 3 log α − 1), where fine-structure constant.). It might be due to contribution of unknown new physics or common systematic problems all previous measurements. method measure directly performed using high power gyrotron. The transition from ortho-positronium para-positronium has been observed with 5 σ CL,...
We report on new results of a search for two-photon interaction with axionlike particles (ALPs). The experiment was carried out at synchrotron radiation facility using "light shining through wall (LSW)" technique. For this purpose, we have developed novel pulsed-magnet system, composed multiple racetrack-magnets and transportable power supply. It produces fields about 10 T over 0.8 m high repetition rate 0.2 Hz yields method probing vacuum intensity fields. data obtained total 27,676 pulses...
We report on the first results from a new dish antenna search for hidden photon dark matter (HPDM) in meV mass region. A double mirror system composed of plane and parabolic is designed to convert HPDMs into photons focused receiver. In this phase 1 experiment we obtain an upper limit photon-HP kinetic mixing $\chi \lesssim 10^{-8}$ range $0.67-0.92\,{\rm meV}$ using conventional mm-wave technology with room-temperature receiver small-sized system.
High precision measurements of the ground state hyperfine structure (HFS) muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants muon magnetic moment and mass, searches new physics. Muonium most suitable system to test QED because both theoretical experimental values can be precisely determined. Previous were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At J-PARC Muon Science...
Abstract J-PARC Muon Facility: MUSE (Muon Science Establishment) is responsible for the inter-university user program and operation, maintenance, construction of muon beamlines, namely D-line, S-line, U-line, H-line, along with source at Materials Life Facility (MLF). In this paper, recent developments are briefly presented.
Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (${\mathrm{Mu}}^{\ensuremath{-}}$), which are bound states of positive muons (${\ensuremath{\mu}}^{+}$) and two electrons, generated from ${\ensuremath{\mu}}^{+}$'s through electron capture process in an aluminum degrader. The ${\mathrm{Mu}}^{\ensuremath{-}}$'s initially electrostatically injected into quadrupole linac (RFQ). In RFQ, to 89 keV. identified momentum measurement time...
At the J-PARC muon facility (MUSE), new beamlines started operation recently. H-line is a high-intensity pulsed beamline for fundamental physics experiments. The first beam of was delivered to its branch (H1 area) in January 2022, where precise measurement muonium hyperfine structure and search μ-e conversion will be conducted. Further extension second g-2/EDM experiment transmission microscope project also ongoing. In addition, surface (S2 area S-line) opened 1S-2S spectroscopy FY2021. this...