A5054292808- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Quantum, superfluid, helium dynamics
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Muon and positron interactions and applications
- Superconducting Materials and Applications
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Medical Imaging Techniques and Applications
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Crystallography and Radiation Phenomena
- Radioactive Decay and Measurement Techniques
- NMR spectroscopy and applications
- Material Properties and Processing
- Advanced Chemical Physics Studies
- Superconducting and THz Device Technology
- Nuclear Materials and Properties
- Cold Fusion and Nuclear Reactions
- High-Energy Particle Collisions Research
Nagoya University
2017-2025
Japan Atomic Energy Agency
2019-2025
Japan Proton Accelerator Research Complex
2019-2024
University of Tsukuba
2014-2015
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,...
Muonic helium is a hydrogenlike atom composed of with one its two electrons replaced by negative muon. Its ground-state hyperfine structure sensitive tool for testing the theory three-body atomic systems and bound-state quantum electrodynamics determining fundamental constants muon magnetic moment mass. New precise measurements are now in progress at J-PARC Muon Science Facility (MUSE). Zero-field have already been carried out, results more than previous 40 years ago. High-field preparation....
We are developing a neutron polarizer with polarized $^3$He gas, referred to as spin filter, based on the Spin Exchange Optical Pumping (SEOP) for scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A gas-filling station was constructed J-PARC, several cells long relaxation times have been fabricated using station. laboratory has prepared in MLF beam hall polarizing cells, compact pumping systems laser powers...
Angular distribution of individual $\gamma$-rays, emitted from a neutron-induced compound nuclear state via radiative capture reaction ${}^{139}$La(n,$\gamma$) has been studied as function incident neutron energy in the epithermal region by using germanium detectors. An asymmetry $A_{\mathrm{LH}}$ was defined $(N_{\mathrm L}-N_{\mathrm H})/(N_{\mathrm L}+N_{\mathrm H})$, where $N_{\mathrm L}$ and H}$ are integrals low high resonance respectively, we found that angular dependence...
Neutron transmission experiments can offer a new type of highly sensitive search for time-reversal invariance violating (TRIV) effects in nucleon-nucleon interactions via the same enhancement mechanism observed large parity (PV) neutron-induced compound nuclear processes. In these processes, TRIV cross section is given as product PV section, spin factor κ, and ratio matrix elements. We determined κ to be 0.59±0.05 139La+n using both (n,γ) spectroscopy (→n+139→La) transmission. This result...
An $sp$-mixing model, which describes a compound nuclear reaction by mixing partial waves, predicts correlation term in this reaction. A detailed study of the model is required to feasibility new type time reversal symmetry violation search experiment. The ${\mathbit{\ensuremath{\sigma}}}_{n}\ifmmode\cdot\else\textperiodcentered\fi{}({\mathbit{k}}_{n}\ifmmode\times\else\texttimes\fi{}{\mathbit{k}}_{\ensuremath{\gamma}})$ $^{139}\mathrm{La}(\stackrel{P\vec}{n},\ensuremath{\gamma})$ has been...
A neutron-energy dependent angular distribution was measured for individual $\ensuremath{\gamma}$ rays from the 3.2 eV $p$-wave resonance of $^{131}\mathrm{Xe}+n$, that shows enhanced parity violation owing to a mixing between $s$- and amplitudes. The $\ensuremath{\gamma}$-ray transitions were identified, with respect neutron momentum evaluated as function energy 7132 keV rays, which correspond transition 1807 excited state $^{132}\mathrm{Xe}$. is considered originate interference...
We present a search for possible spin dependent interactions of the neutron with matter through exchange 1 bosons axial vector couplings as envisioned in extensions Standard Model. This was sought using slow polarimeter that passed transversely polarized neutrons by unpolarized slabs material arranged so this interaction would tilt plane polarization and develop component along momentum. The result rotation angle, $ϕ'_{V_5} = [2.8\pm\,4.6(stat.)\pm\,4.0(sys.)]\times 10^{-5}~\mbox{rad/m}$ is...
The neutron energy-dependent angular distribution of $\ensuremath{\gamma}$ rays from the $^{117}\mathrm{Sn}(n,\ensuremath{\gamma})$ reaction was measured with germanium detectors and a pulsed beam. clearly observed in $\ensuremath{\gamma}$-ray emissions an energy 9327 keV which corresponds to transition resonance $^{117}\mathrm{Sn}+n$ ground state $^{118}\mathrm{Sn}$. causes angular-dependent asymmetric shape. An asymmetry ${A}_{\mathrm{LH}}$ defined as...
Largely enhanced parity-violating effects observed in compound resonances induced by epithermal neutrons are currently attributed to the mixing of parity-unfavored partial amplitudes entrance channel states. Furthermore, it is proposed that same mechanism enhances parity-violation also breaking time-reversal-invariance nucleus. The entrance-channel induces energy-dependent spin-angular correlations individual $\gamma$-rays emitted from nuclear state. For a detailed study model, $\gamma$-ray...
We have developed instruments for magnetic neutron holography (MNH) using polarized white neutrons to investigate the local structures of alloys. chose 3He spin filter method as polarizer polarize over a wide wavelength range up few 100 meV. magnet device saturate magnetizations ferromagnetic samples, and transport from MNH sample. The polarization, , at beginning experiments was confirmed be 0.46, which is feasible MNH. Using instruments, we obtained preliminary results room-temperature...
The mass mμ− of the negative muon is one parameters elementary particle Standard Model and it allows us to verify CPT (charge–parity–time) symmetry theorem by comparing value with mμ+ positive muon. However, experimental determination precision 3.1ppm, which an order magnitude lower than at 120ppb. authors aim determine magnetic moment μμ− a O(10ppb) through spectroscopy hyperfine structure (HFS) muonic helium-4 atom (4Heμ−e−) under high fields. He4μ−e− exotic where two electrons He4...
The small-angle neutron scattering (SANS) and x-ray (SAXS) measurements were performed for deuterated non-deuterated poly(ethylene glycol) (d-PEG h-PEG, respectively) in D2O a D2O/H2O mixed solvent (Mix) to compare the profiles. To determine coherent intensity of SANS, 3He spin filter was utilized. profiles determined by SANS analyzed terms wormlike chain model with touched beads along contour chain. However, SAXS not explained same uniform but each consisting core shell having different...
We measured the spin-dependent cross section at a neutron-induced p-wave resonance using polarized epithermal neutron beam and nuclear target. Our study focuses on 0.75 eV of 139La+n, where previous experiments have shown large enhancement parity violation. The spin dependence absorption 139La neutrons determines partial width resonance. This is key parameter needed to determine sensitivity this system possible parity-odd time reversal-odd interactions beyond standard model. findings...
Abstract To solve the “neutron lifetime puzzle,” where measured neutron lifetimes differ depending on measurement methods, an experiment with a pulsed beam at J-PARC is in progress. In this experiment, neutrons are bunched into 40-cm lengths using spin flip chopper (SFC), statistical sensitivity was limited by aperture size of SFC. The SFC comprises three sets magnetic supermirrors and two resonant flippers. paper, we discuss upgrade to enlarge apertures With upgrade, statistics per unit...
In this study, the germanium detector assembly, installed at Accurate Neutron-Nuclear Reaction measurement Instruments (ANNRI) in Material and Life Science Facility (MLF) operated by Japan Proton Accelerator Research Complex (J-PARC), has been characterized for extension to of angular distribution individual gamma-ray transitions from neutron-induced compound states. We have developed a Monte Carlo simulation code using GEANT4 toolkit, which can reproduce pulse-height spectra gamma-rays...
Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed source was successfully achieved by applying 3 He spin filter as analyzer the neutrons scattered from sample. The cell of gives weak intensity (background) and covers sufficient solid angle performing SANS experiments. relaxation time is continuous use approximately 2 days, thus reaching typical duration required complete set Although accurate evaluation incoherent scattering, which...
The measurement of the ground state hyperfine structure muonic helium has potential to improve precision mass negative muon by a factor 50 or more. is very important because it enables us test CPT theorem comparison with positive mass. We aim measure 1000 times higher than previous experiments [1,2] using highintensity beam at J-PARC and have already obtained results better current in zero-field measurements experiment March 2021. To further precision, we plan high magnetic field incorporate...