A5007195677- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Astronomical and nuclear sciences
- Advanced NMR Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Advanced Chemical Physics Studies
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Quantum, superfluid, helium dynamics
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Magnetic confinement fusion research
- Mass Spectrometry Techniques and Applications
- Inorganic Fluorides and Related Compounds
- Muon and positron interactions and applications
- Astro and Planetary Science
- Rare-earth and actinide compounds
- Ion-surface interactions and analysis
Brookhaven National Laboratory
2023-2025
The University of Tokyo
2015-2024
Osaka University
2022-2024
University of Groningen
2024
RIKEN Nishina Center
2010-2023
Technical University of Darmstadt
2019-2023
Pandora (United States)
2022
RIKEN
2008-2021
University of Tsukuba
2020
Saitama University
2008-2020
The β-decay half-lives of 38 neutron-rich isotopes from (36)Kr to (43)Tc have been measured; the (100)Kr, (103-105)Sr, (106-108)Y, (108-110)Zr, (111,112)Nb, (112-115)Mo, and (116,117)Tc are reported here. results when compared with previous standard models indicate an overestimation in predicted by a factor 2 or more A≈110 region. A revised model based on second generation gross theory β decay better predicts measured suggests rapid flow neutron-capture process (r-matter flow) through this...
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.
We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at RIKEN Radioactive Isotope Beam Factory by using time-of-flight magnetic-rigidity technique. The atomic excesses ^{55-57}Ca are determined for time to be -18650(160), -13510(250), and -7370(990) keV, respectively. examine emergence magicity N=34 based on new masses. masses provide experimental evidence appearance a sizable energy gap between 2p_{1/2} 1f_{5/2} orbitals in ^{54}Ca,...
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...
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...
Excited states in $^{38,40,42}\mathrm{Si}$ nuclei have been studied via in-beam $\ensuremath{\gamma}$-ray spectroscopy with multinucleon removal reactions. Intense radioactive beams of $^{40}\mathrm{S}$ and $^{44}\mathrm{S}$ provided at the new facility RIKEN Radioactive Isotope Beam Factory enabled $\ensuremath{\gamma}\mathrm{\text{\ensuremath{-}}}\ensuremath{\gamma}$ coincidence measurements. A prominent $\ensuremath{\gamma}$ line observed an energy 742(8) keV $^{42}\mathrm{Si}$ confirms...
We report on the measurement of first 2(+) and 4(+) states (66)Cr (70,72)Fe via in-beam γ-ray spectroscopy. The nuclei interest were produced by (p,2p) reactions at incident energies 260 MeV/nucleon. experiment was performed Radioactive Isotope Beam Factory, RIKEN, using DALI 2γ-ray detector array novel MINOS device, a thick liquid hydrogen target combined with vertex tracker. A low-energy plateau 2(1)(+) 4(1)(+) as function neutron number observed for N≥38 N≥40 even-even Cr Fe isotopes,...
In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory RIKEN. The nucleus interest produced through proton knockout from a ^{80}Zn beam 270 MeV/nucleon. level scheme up to 4.6 MeV established for first time and results are compared Monte Carlo shell-model calculations. We do not observe significant feeding excited states below 2.2 MeV, which indicates that Z=28 gap N=50 remains large. show can be described in terms valence outside ^{78}Ni core, implying...
Neutron single particle energies have been measured in 23O using the 22O(d,p)23O*-->22O+n process. The of resonant states deduced to be 4.00(2) MeV and 5.30(4) MeV. first excited state can assigned nu d3/2 from a comparison with shell model calculations. 4.0 energy difference between s1/2 gives size N=16 gap which is agreement recent USD05 ("universal" sd 2005) calculation, large enough explain unbound nature oxygen isotopes heavier than A=24. resonance detected at 5.3 out space. Its...
The low-lying states in ¹⁰⁶Zr and ¹⁰⁸Zr have been investigated by means of β-γ isomer spectroscopy at the radioactive isotope beam factory (RIBF), respectively. A new with a half-life 620 ± 150 ns has identified ¹⁰⁸Zr. For sequence even-even Zr isotopes, excitation energies first 2⁺ reach minimum N = 64 gradually increase as neutron number increases up to 68, suggesting deformed subshell closure 64. ground state indicates that spherical gap predicted 70 is not large enough change shape....
The reduced transition probability $B(E2)\ensuremath{\uparrow}$ of the first excited ${2}^{+}$ state in nucleus $^{104}\mathrm{Sn}$ was measured via Coulomb excitation inverse kinematics at intermediate energies. A value 0.173(28) ${e}^{2}\mathrm{b}{}^{2}$ extracted from absolute cross section on a Pb target. Feeding contributions higher lying states were estimated by reference measurement stable $^{112}\mathrm{Sn}$. Corresponding only to moderate decrease strength relative almost constant...
The formation of a dineutron in the nucleus $^{11}$Li is found to be localized surface region. experiment measured intrinsic momentum struck neutron via $(p,pn)$ knockout reaction at 246 MeV/nucleon. correlation angle between two neutrons is, for first time, as function momentum. A comparison with calculations reveals localization $r\sim3.6$ fm. results also support density dependence deduced from Hartree-Fock-Bogoliubov nuclear matter.
The Rare-RI Ring (R3) is a recently commissioned cyclotron-like storage ring mass spectrometer dedicated to measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. first application measurement using the R3 RIBF reported. Rare isotopes produced RIBF, $^{127}$Sn, $^{126}$In, $^{125}$Cd, $^{124}$Ag, $^{123}$Pd, were injected R3. Masses and $^{123}$Pd measured whereby uncertainty was improved. This reported with new spectrometery technique realized...
Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated variety of sporadic malignancies as well patients with Cowden disease. To investigate the potential role gene renal tumorigenesis, we searched for abnormalities 68 primary renal-cell carcinomas (RCCs) 17...
The electric quadrupole transition from the first ${2}^{+}$ state to ground ${0}^{+}$ in $^{18}\mathrm{C}$ was studied through a lifetime measurement by an upgraded recoil shadow method applied inelastically scattered radioactive nuclei. measured mean is $18.9\ifmmode\pm\else\textpm\fi{}0.9(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}4.4(\mathrm{syst})$ ps, corresponding $B$($E2;{2}_{1}^{+}\ensuremath{\rightarrow}{0}_{\mathrm{g}.\mathrm{s}.}^{+}$) value of...
The structure of neutron-rich isotopes 60Cr and 62Cr was studied via proton inelastic scattering in inverse kinematics. deformation lengths (delta) for were extracted as 1.12(16) 1.36(14) fm, respectively, providing evidence enhanced collectivity these nuclei. An excited state at 1180(10) keV identified the first time. We adopted 4;{+} its spin parity, leading to rapid increase Ex(4;{+})/E_{x}(2;{+}) ratio, which indicates development large near N=40. Importance admixture gd-shell component...
The dependence of the single-particle strength on difference between proton and neutron separation energies is studied for oxygen isotopes in a wide range isospins. cross sections quasi-free (|$p,2p$|) reaction |$^{14,16,18,22,24}$|O were measured at intermediate energies. are compared to predictions based distorted wave impulse approximation shell-model |$psd$| valence-space spectroscopic factors. reduction factors, which ratio experimental theoretical predictions, show no apparent...
Low-energy $\ensuremath{\beta}$-delayed fission of $^{194,196}\mathrm{At}$ and $^{200,202}\mathrm{Fr}$ was studied in detail at the mass separator ISOLDE CERN. The fission-fragment distributions daughter nuclei $^{194,196}\mathrm{Po}$ $^{202}\mathrm{Rn}$ indicate a triple-humped structure, marking transition between asymmetric $^{178,180}\mathrm{Hg}$ symmetric light Ra-Rn nuclei. Comparison with macroscopic-microscopic finite-range liquid-drop model self-consistent approach employing Gogny...
Two-proton relative momentum (qpp) and opening angle (θpp) distributions from the three-body decay of two excited proton-rich nuclei, namely Al23→p+p+Na21 Mg22→p+p+Ne20, have been measured with projectile fragment separator (RIPS) at RIKEN RI Beam Factory. An evident peak qpp∼20 MeV/c as well a in θpp around 30° are seen two-proton break-up channel highly-excited 22Mg. In contrast, such peaks absent for 23Al case. It is concluded that emission mechanism 22Mg quite different case, former...
The key parameter to discuss the possibility of pion condensation in nuclear matter, i.e., so-called Landau-Migdal g^{'}, was extracted by measuring double-differential cross sections for (p,n) reaction at 216 MeV/u on a neutron-rich doubly magic unstable nucleus, ^{132}Sn with quality comparable data taken stable nuclei. strengths Gamow-Teller (GT) transitions from leading ^{132}Sb exhibit GT giant resonance (GTR) excitation energy 16.3±0.4(stat)±0.4(syst) MeV width Γ=4.7±0.8 MeV....
Hyperfine-structure parameters and isotope shifts of $^{195--211}\mathrm{At}$ have been measured for the first time at CERN-ISOLDE, using in-source resonance-ionization spectroscopy method. The hyperfine structures isotopes were recorded a triad experimental techniques monitoring photo-ion current. Multi-Reflection Time-of-Flight Mass Spectrometer, in connection with high-resolution electron multiplier, was used as an ion-counting setup that either affected by strong isobaric contamination...
γ emission probabilities from unbound states in 78,80Se, populated by a neutron-transfer reaction (d,p) on 77,79Se nuclei inverse kinematics, were measured directly detecting residues. Assuming the spin distribution at respective excitation energy of state, cross-sections 79Se(n,γ)80Se evaluated using probabilities. The surrogate-ratio method with experimental 78,80Se was also employed to deduce 79Se(n,γ) incorporating theoretical evaluations neutron-capture isomeric state 77Se. Our two are...