A5005818842- Nuclear physics research studies
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Particle physics theoretical and experimental studies
- Astronomical and nuclear sciences
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Quantum, superfluid, helium dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- X-ray Spectroscopy and Fluorescence Analysis
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- Radiation Therapy and Dosimetry
- Gamma-ray bursts and supernovae
- Particle Accelerators and Free-Electron Lasers
- Boron Compounds in Chemistry
RIKEN Nishina Center
2016-2025
Université Paris-Saclay
2017-2023
Institut de Recherche sur les Lois Fondamentales de l'Univers
2017-2023
CEA Paris-Saclay
2017-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2010-2023
Institute for Basic Science
2023
Ewha Womans University
2023
Technical University of Darmstadt
2023
GSI Helmholtz Centre for Heavy Ion Research
2023
Johannes Gutenberg University Mainz
2019
A long-standing question in nuclear physics is whether chargeless systems can exist. To our knowledge, only neutron stars represent near-pure systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron has been an ongoing quest several decades1, with a particular focus on four-neutron system called tetraneutron, resulting few indications of its existence so far2-4, leaving tetraneutron elusive six...
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 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...
The double-differential cross sections for the Ca48(p,n) and Ti48(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to spectra extract Gamow-Teller (GT) components. integrated GT strengths up an excitation energy of 30 MeV in Sc48 are 15.3±2.2 2.8±0.3 (p,n) (n,p) spectra, respectively. In additional found above 8 where shell models within fp shell-model space predict almost no strengths, suggesting that present description nuclear matrix element...
A new technique to measure $(p,n)$ charge-exchange reactions in inverse kinematics at intermediate energies on unstable isotopes was successfully developed and used study the $^{56}\mathrm{Ni}(p,n)$ reaction $110\text{ }\text{ }\mathrm{MeV}/\mathrm{u}$. Gamow-Teller transition strengths from $^{56}\mathrm{Ni}$ leading $^{56}\mathrm{Cu}$ were obtained compared with shell-model predictions $pf$ shell using KB3G GXPF1A interactions. The calculations interaction reproduce experimental strength...
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...
The first $\ensuremath{\gamma}$-ray spectroscopy of $^{52}\mathrm{Ar}$, with the neutron number $N=34$, was measured using $^{53}\mathrm{K}(p,2p)$ one-proton removal reaction at $\ensuremath{\sim}210\text{ }\text{ }\mathrm{MeV}/\mathrm{u}$ RIBF facility. ${2}_{1}^{+}$ excitation energy is found 1656(18) keV, highest among Ar isotopes $N>20$. This result experimental signature persistence $N=34$ subshell closure beyond $^{54}\mathrm{Ca}$, i.e., below magic proton $Z=20$. Shell-model...
Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a $^{54}\mathrm{Ca}$ beam striking on liquid hydrogen target at $\ensuremath{\sim}200\text{ }\text{ }\mathrm{MeV}/u$. A significantly larger section to the ${p}_{3/2}$ state compared ${f}_{5/2}$ observed in excitation of $^{53}\mathrm{Ca}$ provides direct evidence nature $N=34$ shell closure. This finding corroborates arising new closure neutron-rich calcium isotopes. The...
The cluster structure of the neutron-rich isotope ^{10}Be has been probed via (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and quasifree conditions. populated states ^{6}He residues were investigated through missing mass spectroscopy. triple differential cross section for ground-state transition was extracted angle pairs (θ_{p},θ_{α}) compared to distorted-wave impulse approximation calculations performed a microscopic framework using successively Tohsaki-Horiuchi-Schuck-Röpke...
The origin of the highest energy cosmic rays (≥1020 eV) is not well understood. Interesting models called "top-down" scenarios have been proposed to explain origin. γ-ray flux in ultra-high-energy a key parameter for giving constraints on such models. To study properties showers, we carry out simulation studies that take into account both Landau-Pomeranchuk-Migdal effect and electromagnetic interactions geomagnetic field. Based an analysis muons air showers observed by Akeno Giant Air Shower...
Three precise measurements for elastic $pd$ scattering at $135\text{ }\text{ }\mathrm{MeV}/A$ have been performed with the three different experimental setups. The cross sections are described well by theoretical predictions based on modern nucleon-nucleon forces combined three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects restricted to backward angles. This result supports two recently reported RIKEN and contradicts KVI data.
The differential cross sections and vector analyzing powers for nd elastic scattering at En=248 MeV were measured 10°–180° in the center-of-mass (c.m.) system. To cover wide angular range, experiments performed separately by using two different setups forward backward angles. data are compared with theoretical results based on Faddeev calculations realistic nucleon-nucleon (NN) forces such as AV18, CD Bonn, Nijmegen I II, their combinations three-nucleon (3NFs), Tucson-Melbourne 99 (TM99),...
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.
We report the results of first-time test local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs massive spin $1/2$ hadrons from decay short-lived ($\ensuremath{\tau}<{10}^{\ensuremath{-}21}\mathrm{sec}$) $^{2}\mathrm{He}$ spin-singlet state, populated in nuclear reaction $^{2}\mathrm{H}+^{1}\mathrm{H}\ensuremath{\rightarrow}^{2}\mathrm{He}+n$. The novel features this experiment are (a) use an ``event-ready'' detector nearly 100% efficiency...
The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use a newly constructed solid proton target operated in low magnetic field and high temperature. Two approaches based on local one-body potentials were applied to investigate spin-orbit interaction between nucleus. An optical model analysis revealed that potential is characterized by shallow long-ranged shape compared with global systematics stable...
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...
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....
Excited states in the $N=40$ isotone $^{62}$Ti were populated via $^{63}$V$(p,2p)$$^{62}$Ti reaction at $\sim$200~MeV/u Radioactive Isotope Beam Factory and studied using $γ$-ray spectroscopy. The energies of $2^+_1 \rightarrow 0^{+}_{\mathrm{gs}}$ $4^+_1 2^+_1$ transitions, observed here for first time, indicate a deformed ground state. These are increased compared to neighboring $^{64}$Cr $^{66}$Fe isotones, suggesting small decrease quadrupole collectivity. present measurement is well...
We report on the first γ-ray spectroscopy of 51,53K produced via 52,54Ca(p,2p) reactions at ∼250 MeV/nucleon. Unambiguous final-state angular-momentum assignments were achieved for beam intensities down to few particles per second by using a new technique based reaction vertex tracking combined with thick liquid-hydrogen target. Through and exclusive parallel momentum distribution analysis, 3/2+ ground states 1/2+ excited in established quantifying natural ordering 1d3/2 2s1/2 proton-hole...