A5013117789- Nuclear physics research studies
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Neutrino Physics Research
- Astronomical and nuclear sciences
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Quantum, superfluid, helium dynamics
- Particle physics theoretical and experimental studies
- Inorganic Fluorides and Related Compounds
- Quantum chaos and dynamical systems
- Muon and positron interactions and applications
- Radiopharmaceutical Chemistry and Applications
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Crystallography and Radiation Phenomena
- Crystallization and Solubility Studies
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Superconductivity in MgB2 and Alloys
- Particle accelerators and beam dynamics
Osaka University
2016-2025
Joint Institute for Nuclear Astrophysics
2021
iThemba Laboratory
2005-2016
University of the Witwatersrand
2004-2016
National Research Foundation
2009-2013
University of Notre Dame
2012
University of Cape Town
2009
Stellenbosch University
2009
University of Birmingham
2009
Helmholtz-Zentrum Berlin für Materialien und Energie
2009
A benchmark experiment on 208Pb shows that polarized proton inelastic scattering at very forward angles including 0{\deg} is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic (M1) modes in nuclei over broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads neutron skin thickness r_skin = 0.156+0.025-0.021 fm derived within mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry its...
A high-energy-resolution magnetic spectrometer has been used to measure the $^{12}\mathrm{C}$ excitation energy spectrum search for ${2}^{+}$ of 7.65 MeV, ${0}^{+}$ Hoyle state. By measuring in diffractive minimum angular distribution broad background, evidence is found a possible state at 9.6(1) MeV with width 600(100) keV. The implications $^{8}\mathrm{Be}+^{4}\mathrm{He}$ reaction rate stellar environments are discussed.
The electric dipole strength distribution in 120Sn between 5 and 22 MeV has been determined at RCNP Osaka from a polarization transfer analysis of proton inelastic scattering E_0 = 295 forward angles including 0{\deg}. Combined with photoabsorption data an polarizability \alpha_D(120Sn) 8.93(36) fm^3 is extracted. as isovector observable par excellence carries direct information on the nuclear symmetry energy its density dependence. correlation new value well established \alpha_D(208Pb)...
The Gamow-Teller (GT) strength distribution has been investigated in a high-resolution (${}^{3}$He,$t$) charge-exchange experiment on the double-beta ($\ensuremath{\beta}\ensuremath{\beta}$) decaying nucleus ${}^{100}$Mo. was carried out at Osaka University Research Center for Nuclear Physics (RCNP) with 420 MeV incident ${}^{3}$He beam and Grand Raiden magnetic spectrometer. A final-state energy resolution of 33 keV achieved. It found that nearly entire low-energy (up to...
Scattering of protons several hundred MeV is a promising new spectroscopic tool for the study electric dipole strength in nuclei. A case 208Pb shows that at very forward angles J^pi = 1- states are strongly populated via Coulomb excitation. separation from nuclear excitation other modes achieved by multipole decomposition analysis experimental cross sections based on theoretical angular distributions calculated within quasiparticle-phonon model. The B(E1) transition distribution extracted...
The electric dipole strength in 120Sn has been extracted from proton inelastic scattering experiments at E_p = 295 MeV and forward angles including 0 degree. Below neutron threshoild it differs the results of a 120Sn(gamma,gamma') experiment peaks an excitation energy 8.3 MeV. total corresponds to 2.3(2)% energy-weighted sum rule is more than three times larger what observed with (gamma,gamma') reaction. This implies strong fragmentation E1 and/or small ground state branching ratios excited...
This study investigated the asymmetry among analogous spin-isospin-flip transition strengths from [𝐽𝜋,𝑇]=[1+,0]1 ground state of 14N to [2+,1]1 and [2+,1]2 states in 𝐴=14 nuclei 146C8, 147N7, 148O6. The reduced for excited 14N, denoted by 𝐵(GT0), were obtained via a 14N(𝑝,𝑝′) experiment at 𝐸𝑝=200 MeV performed iThemba LABS, South Africa. 𝐵(GT0) values compared with 𝐵(GT+) 𝐵(GT−) 14C 14O, which are available charge-exchange reaction measurements. Based on simple two-state model, off-diagonal...
A ${}^{76}$Ge(${}^{3}$He,$t$)${}^{76}$As charge-exchange experiment at an incident energy of 420 MeV has been performed with resolution 30 keV. The Gamow-Teller GT${}^{\ensuremath{-}}$ strength distribution in ${}^{76}$As, which is the intermediate nucleus double-beta ($\ensuremath{\beta}\ensuremath{\beta}$) decay ${}^{76}$Ge, extracted. An unusually strong fragmentation observed even low excitation energies...
Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The GT excitations were studied for the mass number $A=42$, 46, 50, 54 ``$f$-shell'' ($^{3}\mathrm{He}$, $t$) charge-exchange reactions. In $^{42}\mathrm{Ca}\ensuremath{\rightarrow}^{42}\mathrm{Sc}$ reaction, most of strength is concentrated lowest excited state at 0.6 MeV, suggesting existence a low-energy phonon excitation. As $A$ increases, high-energy...
The $^{150}\mathrm{Nd}$($^{3}\mathrm{He}$,$t$) reaction at $140$ MeV/u and $^{150}\mathrm{Sm}$($t$,$^{3}\mathrm{He}$) $115$ were measured, populating excited states in $^{150}\mathrm{Pm}$. transitions studied populate intermediate of importance for the (neutrinoless) $\ensuremath{\beta}\ensuremath{\beta}$ decay $^{150}\mathrm{Nd}$ to $^{150}\mathrm{Sm}$. Monopole dipole contributions measured excitation-energy spectra extracted by using multipole decomposition analyses. experimental results...
A (${}^{3}\text{He},t$) charge-exchange reaction experiment on the double-beta decaying nucleus ${}^{136}$Xe has been performed at an incident energy of 420 MeV with objective to measure Gamow-Teller (GT) strength distribution in ${}^{136}$Cs. The measurements have carried out dispersion-matched WS beam line and Grand Raiden spectrometer Research Center for Nuclear Physics Osaka, where resolution 42 keV was achieved. new gas cell thin windows made polyethylene naphthalate employed as a...
A high-resolution measurement of inelastic proton scattering off $^{90}\mathrm{Zr}$ near 0\ifmmode^\circ\else\textdegree\fi{} was performed at 295 MeV with a focus on pronounced strength previously reported in the low-energy tail giant dipole resonance. forest fine structure observed excitation energy region 7--12 MeV. multipole decomposition analysis angular distribution for carried out using ECIS95 distorted-wave Born approximation code Hartree-Fock plus random-phase model $E1$ and $M1$...
Gamow-Teller (GT) strength distributions have been investigated in a high-resolution (${}^{3}$He,$t$) charge-exchange experiment on the double-$\ensuremath{\beta}$ ($\ensuremath{\beta}\ensuremath{\beta}$ ) decaying nuclei ${}^{128}$Te and ${}^{130}$Te. The was carried out at Research Center for Nuclear Physics, Osaka, with 420-MeV incident ${}^{3}$He beam Grand Raiden magnetic spectrometer. A final-state energy resolution of 35 keV achieved. extracted GT low excitation energies final...
The gamma strength function and level density of ${1}^{\ensuremath{-}}$ states in $^{96}\mathrm{Mo}$ have been extracted from a high-resolution study the ($\stackrel{\ensuremath{\rightarrow}}{p}$, ${\stackrel{\ensuremath{\rightarrow}}{p}}^{\ensuremath{'}}$) reaction at 295 MeV extreme forward angles. By comparison with compound nucleus $\ensuremath{\gamma}$ decay experiments, this allows test generalized Brink-Axel hypothesis energy region pygmy dipole resonance. is commonly assumed...
Differential cross sections of isoscalar and isovector spin-M1 (0(+)→1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295 MeV on (24)Mg, (28)Si, (32)S, (36)Ar 0°-14°. The squared nuclear transition matrix elements deduced from the differential by applying empirically determined unit based assumption isospin symmetry. ratios accumulated up to E(x)=16 compared a shell-model prediction 1.01(9) for 0.61(6) transitions, respectively. Thus, no...
The $^{22}$Ne($\alpha$,n)$^{25}$Mg reaction is the dominant neutron source for slow capture process ($s$-process) in massive stars and contributes, together with $^{13}$C($\alpha$,n)$^{16}$O, to production of neutrons $s$-process Asymptotic Giant Branch (AGB) stars. However, endothermic competes directly $^{22}$Ne($\alpha,\gamma)^{26}$Mg radiative capture. uncertainties both reactions are large owing uncertainty level structure $^{26}$Mg near alpha separation energies. These affecting...
Fine structure in the energy region of isoscalar giant quadrupole resonance nuclei is observed high-resolution proton scattering experiments at iThemba LABS over a wide mass range. A novel method based on wavelet transforms introduced for extraction scales characterizing fine structure. comparison with microscopic model calculations including two-particle two-hole (2p2h) degrees freedom identifies coupling to surface vibrations as main source scales. generic pattern also found stochastic...
The fine structure of the Gamow-Teller resonance in a medium-heavy nucleus is observed for first time high-resolution $^{90}\mathrm{Zr}(^{3}\mathrm{He},t)^{90}\mathrm{Nb}$ experiment at Research Center Nuclear Physics, Osaka. Using novel wavelet analysis technique, it possible to extract characteristic energy scales and quantify their relative importance generation structure. This method combined with selectivity reaction permits an extraction level density ${1}^{+}$ states $^{90}\mathrm{Nb}$.
To study the Gamow-Teller (GT) transitions from ${T}_{z}=+1$ nucleus $^{42}\text{Ca}$ to ${T}_{z}=0$ $^{42}\text{Sc}$, where ${T}_{z}$ is $z$ component of isospin $T$, we performed a ($p,n$)-type $(^{3}\text{He},t)$ charge-exchange reaction at 140 MeV/nucleon and scattering angles around ${0}^{\ensuremath{\circ}}$. With an energy resolution 29 keV, states excited by GT (GT states) could be studied accurately. The reduced transition strengths $B(\text{GT})$ were derived up excitation 13 MeV,...
We report the observation of a very exotic decay mode at proton drip line, β-delayed γ-proton decay, clearly seen in β Tz=−2 nucleus Zn56. Three sequences have been observed after decay. Here this mode, already sd shell, is for first time fp shell. Both γ and decays taken into account estimation Fermi Gamow-Teller strengths. Evidence fragmentation strength due to strong isospin mixing found.Received 13 February 2014DOI:https://doi.org/10.1103/PhysRevLett.112.222501© 2014 American Physical Society
Background: There is renewed interest in electric dipole strength distributions for a variety of reasons including the extraction polarizability related to properties symmetry energy and measure neutron skin thickness, understanding structure low-energy $E1$ nuclei with excess, establishing systematics isovector giant resonance (IVGDR). Inelastic proton scattering at energies few hundred MeV very forward angles ${0}^{\ensuremath{\circ}}$ has been established as tool study magnetic...