A5069454545- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Astronomical and nuclear sciences
- Advanced Chemical Physics Studies
- Superconducting and THz Device Technology
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Nuclear reactor physics and engineering
- Physics of Superconductivity and Magnetism
- Particle physics theoretical and experimental studies
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Spectroscopy and Laser Applications
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Cold Atom Physics and Bose-Einstein Condensates
- Terahertz technology and applications
- Advanced Semiconductor Detectors and Materials
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
RIKEN Nishina Center
2016-2025
Seoul National University
2013-2024
The University of Tokyo
1998-2024
Gifu Pharmaceutical University
2023
Tokyo Institute of Technology
2009-2023
Institute for Basic Science
2017-2023
Tohoku University
2009-2023
GSI Helmholtz Centre for Heavy Ion Research
2023
Shibaura Institute of Technology
2023
Kyushu University
2019
Precise measurements of deuteron vector and tensor analyzing powers ${A}_{y}^{d},$ ${A}_{\mathrm{xx}},$ ${A}_{\mathrm{yy}},$ ${A}_{\mathrm{xz}}$ in $d\ensuremath{-}p$ elastic scattering were performed via ${}^{1}\mathrm{H}(\stackrel{\ensuremath{\rightarrow}}{d},d)p$ ${}^{1}\mathrm{H}(\stackrel{\ensuremath{\rightarrow}}{d},p)d$ reactions at three incoming energies ${E}_{d}^{\mathrm{lab}}=140,$ 200, $270 \mathrm{MeV}.$ A wide range center-of-mass angles from...
A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238 U beam has been carried out at the RI Beam Factory RIKEN Nishina Center. Fission fragments were analyzed and identified by superconducting separator BigRIPS. We observed 45 neutron-rich isotopes: 71 Mn, 73,74 Fe, 76 Co, 79 Ni, 81,82 Cu, 84,85 Zn, 87 Ga, 90 Ge, 95 Se, 98 Br, 101 Kr, 103 Rb, 106,107 Sr, 108,109 Y, 111,112 Zr, 114,115 Nb, 115,116,117 Mo, 119,120 Tc, 121,122,123,124 Ru, 123,124,125,126 Rh, 127,128 Pd, 133...
The cross sections for single-neutron removal from the very neutron-rich nucleus $^{31}\mathrm{Ne}$ on Pb and C targets have been measured at $230\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$ using RIBF facility RIKEN. deduced large Coulomb breakup section of 540(70) mb is indicative a soft $E1$ excitation. Comparison with direct-breakup model calculations suggests that valence neutron occupies low-$\ensuremath{\ell}$ orbital (most probably $2{p}_{3/2}$) small separation energy...
The double differential cross sections at ${\ensuremath{\theta}}_{\mathrm{lab}}$ between $0.0\ifmmode^\circ\else\textdegree\fi{}$ and $12.3\ifmmode^\circ\else\textdegree\fi{}$ the polarization transfer ${D}_{\mathrm{NN}}$ $0\ifmmode^\circ\else\textdegree\fi{}$ for ${}^{90}\mathrm{Zr}(p,n)$ reaction are measured a bombarding energy of 295 MeV. A multipole decomposition technique is applied to extract $L=0$, $L=1$, $L=2$, $L=3$ contributions. Gamow-Teller (GT) strength $B(\mathrm{GT})$ in...
A search for isomeric \ensuremath{\gamma} decays among fission fragments from 345 MeV/nucleon ${}^{238}$U has been performed at the RIKEN Nishina Center RI Beam Factory. Fission were selected and identified using superconducting in-flight separator BigRIPS implanted in an aluminum stopper. Delayed rays detected three clover-type high-purity germanium detectors located focal plane within a time window of 20 \ensuremath{\mu}s following implantation. We total 54 microsecond isomers with...
A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of 0.83±0.65(stat)±1.25(syst) MeV above threshold four-neutron decay with a significance level 4.9σ. Utilizing large positive Q value (^{8}He,^{8}Be) reaction, an almost recoilless condition system was achieved so as to obtain weakly interacting efficiently.
A search for the heaviest isotopes of fluorine, neon, and sodium was conducted by fragmentation an intense Ca48 beam at 345 MeV/nucleon with a 20-mm-thick beryllium target identification in large-acceptance separator BigRIPS RIKEN Radioactive Isotope Beam Factory. No events were observed F32,33, Ne35,36, Na38 only one event Na39 after extensive running. Comparison predicted yields excludes existence bound states these unobserved high confidence levels. The present work indicates that F31...
Cross sections of 1n-removal reactions from the neutron-rich nucleus Mg37 on C and Pb targets parallel momentum distributions residues target have been measured at 240 MeV/nucleon. A combined analysis these distinct nuclear- Coulomb-dominated reaction data shows that ground state has a small 1n separation energy 0.22−0.09+0.12 MeV an appreciable p-wave neutron single-particle strength. These results confirm lies near edge "island inversion" sizable halo component, heaviest such system...
The unbound nucleus O26 has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a F27 beam at 201 MeV/nucleon. decay products, O24 and two neutrons, were detected in coincidence the newly commissioned SAMURAI spectrometer RIKEN Radioactive Isotope Beam Factory. ground-state resonance was found to lie only 18±3(stat)±4(syst) keV above threshold. In addition, higher lying level, which is most likely first 2+ state, observed for time 1.28−0.08+0.11 MeV...
The interaction cross sections (σI) of the very neutron-rich carbon isotopes 19C, 20C and 22C have been measured on a target at 307, 280, 235 MeV/nucleon, respectively. A σI 1.280±0.023 b was obtained for 22C, significantly larger than 19,20C, supporting halo character 22C. root-mean-squared matter radius 3.44±0.08 fm deduced using four-body Glauber reaction model. This value is smaller an earlier estimate (of 5.4±0.9 fm) derived from measurement hydrogen 40 MeV/nucleon. These new,...
The discovery of the important neutron-rich nucleus 6020Ca40 and seven others near limits nuclear stability is reported from fragmentation a 345 MeV/u 70Zn projectile beam on 9Be targets at radioactive ion-beam factory RIKEN Nishina Center. produced fragments were analyzed unambiguously identified using BigRIPS two-stage in-flight separator. eight new nuclei discovered, 47P, 49S, 52Cl, 54Ar, 57K, 59,60Ca, 62Sc, are most isotopes respective elements. In addition, one event consistent with 59K...
A kinematically complete quasi-free $(p,pn)$ experiment in inverse kinematics was performed to study the structure of Borromean nucleus $^{17}$B, which had long been considered have neutron halo. By analyzing momentum distributions and exclusive cross sections, we obtained spectroscopic factors for $1s_{1/2}$ $0d_{5/2}$ orbitals, a surprisingly small percentage 9(2)$\%$ determined $1s_{1/2}$. Our finding such component halo features reported prior experiments can be explained by deformed...
Subjecting a physical system to extreme conditions is one of the means often used obtain better understanding and deeper insight into its organization structure. In case atomic nucleus, such approach investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich exhibit most asymmetric N/Z those lying beyond limits binding, which undergo spontaneous neutron emission exist only as short-lived resonances (about 10-21 s), provide...
The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for first time, with energies 0.84(3) 2.15(5) MeV above two-neutron threshold widths 0.32(8) 0.95(15) MeV, respectively. These assigned to be ground (J^{π}=0^{+}) excited (2^{+}) state, E_{x}=1.31(6) MeV. mass excess ^{16}Be was thus deduced 56.93(13) some 0.5 more bound than only previous...
Excess nucleons in neutron- or proton-rich nuclei are expected to play a distinctive role because of loose coupling core. The Steinwedel and Jensen hydrodynamic model is used examine the possible existence new type dipole oscillation which core excess parts vibrate against each other.
The cross section, the deuteron vector A(d)(y) and tensor analyzing powers A(ij), polarization transfer coefficients K(y('))(ij), induced P(y(')) were measured for dp elastic scattering at 270 MeV. section are well reproduced by Faddeev calculations with modern data-equivalent nucleon-nucleon forces plus Tucson-Melbourne three-nucleon force. In contrast, or not described such calculations. These facts indicate deficiencies in spin dependence of force call extended models.
We report on the first spectroscopic study of N=22 nucleus 32Ne at newly completed RIKEN Radioactive Ion Beam Factory. A single gamma-ray line with an energy 722(9) keV was observed in both inelastic scattering a 226 MeV/u beam carbon target and proton removal from 33Na 245 MeV/u. This transition is assigned to deexcitation Jpi=2+ state 0+ ground state. Interpreted through comparison state-of-the-art shell-model calculations, low excitation demonstrates that "island inversion" extends least...
The unbound excited states of the neutron drip-line isotope 24O have been investigated via 24O(p,p′)23O+n reaction in inverse kinematics at a beam energy 62 MeV/nucleon. decay spectrum 24O∗ was reconstructed from momenta 23O and neutron. spin parity first state, observed Ex=4.65±0.14 MeV, determined to be Jπ=2+ angular distribution cross section. Higher-lying were also observed. quadrupole transition parameter β2 2+1 state deduced, for time, 0.15±0.04. relatively high excitation small value...
The structure of $^{19,20,22}$C has been investigated using high-energy (about 240 MeV/nucleon) one- and two-neutron removal reactions on a carbon target. Measurements were made the inclusive cross sections momentum distributions for charged residues. Narrow observed one-neutron from $^{19}$C $^{20}$C $^{22}$C. Two-neutron resulted in relatively broad distribution. results are compared with eikonal-model calculations combined shell-model information. neutron-removal associated calculated...
The halo structure of 31Ne is studied using 1n-removal reactions on C and Pb targets at 230 MeV/nucleon. A combined analysis the cross sections these nuclear Coulomb dominated that feed directly 30Ne ground-state reveals to have a small neutron separation energy, 0.15+0.16−0.10 MeV, spin-parity 3/2−. Consistency data with reaction large-scale shell-model calculations identifies as deformed having significant p-wave component, suggesting halos are more frequent occurrences drip line.Received...
The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold an integrated E1 B(E1)=1.64±0.06(stat)±0.12(sys) e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft excitation, provides first firm evidence that prominent halo. Three-body...