H. Tatsuno
A5002630619- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Superconducting and THz Device Technology
- Physics of Superconductivity and Magnetism
- Nuclear physics research studies
- High-pressure geophysics and materials
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Geophysics and Gravity Measurements
- Superconducting Materials and Applications
- Superconductivity in MgB2 and Alloys
- Magnetic confinement fusion research
- Earthquake Detection and Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Astrophysical Phenomena and Observations
- Muon and positron interactions and applications
- Radioactive element chemistry and processing
Lund University
2016-2024
Tokyo Metropolitan University
2019-2024
Tokyo Institute of Technology
2022
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2011-2019
Osaka University
2019
Sapienza University of Rome
2019
Istituto Nazionale di Fisica Nucleare
2019
The University of Tokyo
2006-2017
High Energy Accelerator Research Organization
2016-2017
National Institute of Standards and Technology
2015-2017
The $\bar{K}N$ system at threshold is a sensitive testing ground for low energy QCD, especially the explicit chiral symmetry breaking. Therefore, we have measured $K$-series x rays of kaonic hydrogen atoms DA$\Phi$NE electron-positron collider Laboratori Nazionali di Frascati, and determined most precise values strong-interaction energy-level shift width $1s$ atomic state. As x-ray detectors, used large-area silicon drift detectors having excellent timing resolution, which were developed...
Combined X-ray free-electron laser techniques pinpoints loci of intersections between potential energy surfaces a photo-excited 3d transition-metal centered molecule.
We describe a series of microcalorimeter X-ray spectrometers designed for broad suite measurement applications. The chief advantage this type spectrometer is that it can be orders magnitude more efficient at collecting X-rays than traditional high-resolution rely on wavelength-dispersive techniques. This most useful in applications are traditionally photon-starved and/or involve radiation-sensitive samples. Each energy-dispersive built around an array several hundred transition-edge sensors...
Kaonic atoms are exotic atomic systems where an electron is replaced by a negatively charged kaon which also experiences the strong interaction with nucleus. Precision spectroscopy of kaonic represents excellent tool to study particles strangeness. This work reviews progress and prospects in modern era atom experiments, discusses constraints on low-energy theories strangeness sector.
Disentangling the dynamics of electrons and nuclei during nonadiabatic molecular transformations remains a considerable experimental challenge. Here we have investigated photoinduced electron transfer following metal-to-ligand charge-transfer (MLCT) excitation [Fe(bmip)2]2+ photosensitizer, where bmip = 2,6-bis(3-methyl-imidazole-1- ylidine)-pyridine, with simultaneous femtosecond-resolution Fe K{\alpha} K\b{eta} X-ray Emission Spectroscopy (XES) Wide Angle Scattering (WAXS). This...
We observed a distinct peak in the Λp invariant mass spectrum of He3(K−,Λp)n, well below mK+2mp, i.e., threshold K− to be bound two protons. By selecting relatively large momentum-transfer region q=350∼650 MeV/c, one can kinematically separate from quasi-free process, K‾N→K‾N followed by non-resonant absorption spectator-nucleons K‾NN→ΛN. found that simplest fit gives us Breit–Wigner pole position at BKpp=47±3(stat.)−6+3(sys.) MeV having width ΓKpp=115±7(stat.)−20+10(sys.) MeV, and S-wave...
We have measured the Balmer-series x-rays of kaonic $^4$He atoms using novel large-area silicon drift x-ray detectors in order to study low-energy $\bar{K}$-nucleus strong interaction. The energy $3d \to 2p$ transition was determined be 6467 $\pm$ 3 (stat) 2 (syst) eV. resulting strong-interaction energy-level shift is agreement with theoretical calculations, thus eliminating a long-standing discrepancy between theory and experiment.
By combining transient X-ray and optical studies, we reveal the solvent influence on excited state potential energy surfaces of [Fe(bpy)(CN)<sub>4</sub>]<sup>2−</sup>.
Iron N-heterocyclic carbene (NHC) complexes have received a great deal of attention recently because their growing potential as light sensitizers or photocatalysts. We present sub-ps X-ray spectroscopy study an FeII NHC complex that identifies and quantifies the states involved in deactivation cascade after absorption. Excited molecules relax back to ground state along two pathways: After population hot 3 MLCT state, from initially excited 1 30 % undergo ultrafast (150 fs) relaxation MC...
The kaonic (3)He and (4)He X-rays emitted in the [Formula: see text] transitions were measured SIDDHARTA experiment. widths of 2p states determined to be text], respectively. Both results are consistent with theoretical predictions. width is much smaller than value by experiments performed 70's 80's, while was for first time.
Probing electronic states on ultrafast timescales is critical for studies of chemical reactions. A tabletop method performing time-resolved x-ray emission spectroscopy presented and tested using a polypyridyl iron complex.
We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). determined energies to be 6224.5±0.4(stat)±0.2(syst) 6463.7±0.3(stat)±0.1(syst) eV, widths 2.5±1.0(stat)±0.4(syst) 1.0±0.6(stat)±0.3(stat) for ^{4}He, respectively. These values are nearly 10 times more precise in previous measurements. Our results exclude large strong-interaction shifts that suggested...
To search for an |${\rm S} = -1$| di-baryonic state which decays to |$\Lambda p$|, the |${}^3{\rm He}(K^-,\Lambda p)n_{\rm missing}$| reaction was studied at 1.0 GeV}/c$|. Unobserved neutrons were kinematically identified from missing mass |$M_{X}$| of p)X$| in order have a large acceptance pn$| final state. The observed events, distributed widely over allowed region Dalitz plot, establish that major component comes three-nucleon absorption process. A concentration events specific neutron...
High-resolution pionic atom X-ray spectroscopy was performed with an spectrometer based on a 240 pixel array of superconducting transition-edge sensor (TES) microcalorimeters at the πM1 beam line Paul Scherrer Institute. X-rays emitted by carbon via 4f→3d transition and parallel 4d→3p were observed full width half maximum energy resolution 6.8 eV 6.4 keV. The measured energies are consistent calculated electromagnetic values which considered strong interaction effect assessed Seki–Masutani...
We have performed an exclusive measurement of the K−+He3→Λpn reaction at incident kaon momentum 1GeV/c. In Λp invariant mass spectrum, a clear peak was observed below threshold K¯+N+N, as signal kaonic nuclear bound state, K¯NN. The binding energy, decay width, and S-wave Gaussian form factor this state were to be BK=42±3(stat.)−4+3(syst.)MeV, ΓK=100±7(stat.)−9+19(syst.)MeV, QK=383±11(stat.)−1+4(syst.)MeV/c, respectively. total production cross section K¯NN, determined by its mode,...
We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile characteristic Kα and Kβ together with hypersatellite Khα around 6 keV. This signature reflects time-dependent screening nuclear charge by negative muon L-shell electrons, accompanied electron side feeding. Assisted a simulation, these data clearly reveal K- hole production...
To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of $5g--4f$ and $5f--\text{ }4d$ transitions (BSQED contribution 2.4 5.2 eV, respectively) muonic neon atoms low-pressure gas phase without bound electrons. Muonic been recently proposed as an alternative to few-electron high-$Z$ ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined...
An experiment to search for the $K^-pp$ bound state was performed via in-flight $^3$He($K^-,n)$ reaction using 5.3 $\times$ $10^9$ kaons at 1 GeV/$c$ J-PARC hadron experimental facility. In semi-inclusive neutron missing-mass spectrum $\theta_{n}^{lab}=0^\circ$, no significant peak observed in region corresponding binding energy larger than 80 MeV, where a bump structure has been reported $\Lambda p$ final different reactions. Assuming be isotropically decaying into p$, mass-dependent upper...