A5025030010- Nuclear physics research studies
- Astronomical and nuclear sciences
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Quantum Chromodynamics and Particle Interactions
- Advanced NMR Techniques and Applications
- Chemical Thermodynamics and Molecular Structure
- Nuclear Materials and Properties
- Radioactive Decay and Measurement Techniques
- Atomic and Molecular Physics
- Cold Atom Physics and Bose-Einstein Condensates
- High-pressure geophysics and materials
- History and advancements in chemistry
- High-Energy Particle Collisions Research
- Advanced Chemical Physics Studies
- Atomic and Subatomic Physics Research
- Quantum chaos and dynamical systems
- Molecular spectroscopy and chirality
- Catalysis and Oxidation Reactions
- X-ray Diffraction in Crystallography
- Pulsars and Gravitational Waves Research
- Rare-earth and actinide compounds
- Heavy Metals in Plants
- Material Science and Thermodynamics
- Neutrino Physics Research
Michigan State University
2022-2024
Mississippi State University
2013-2021
Ghana Atomic Energy Commission
2010-2021
UNSW Sydney
2020
University of Ghana
2011
Covariant density functional theory is a modern theoretical tool for the description of nuclear structure phenomena. The current investigation aims at global assessment accuracy ground state properties even-even nuclei. We also estimate uncertainties defined here as spreads predictions within four covariant energy functionals in known regions chart and their propagation towards neutron drip line. Large-scale axial relativistic Hartree-Bogoliubov calculations are performed all...
A systematic investigation of octupole-deformed nuclei is presented for even-even systems with $Z\ensuremath{\le}106$ located between the two-proton and two-neutron driplines. For this study we use five most-up-to-date covariant energy density functionals different types, a nonlinear meson coupling, density-dependent couplings, zero-range interactions. Pairing correlations are treated within relativistic Hartree-Bogoliubov theory based on an effective separable particle-particle interaction...
The sources of theoretical uncertainties in the prediction two-neutron drip line are analyzed framework covariant density functional theory. We concentrate on single-particle and pairing properties as potential these uncertainties. major source can be traced back to differences underlying structure various energy functionals (CEDF). It is found that description energies at dominated by those existing already known nuclei. Only approximately one third due isovector channel CEDF's. Thus,...
The phenomenon of reflection-asymmetric nuclear shapes is relevant to stability, spectroscopy, decays and fission, the search for new physics beyond standard model. Global surveys ground-state octupole deformation, performed with a limited number models, suggest that pear-shaped isotopes fairly across landscape. We carry out global analysis deformations particle-bound even-even nuclei $Z \leq 110$ $N 210$ using density functional theory (DFT) several non-relativistic covariant energy...
A systematic investigation of even-even superheavy elements in the region proton numbers $100 \leq Z 130$ and neutron from proton-drip line up to number $N=196$ is presented. For this study we use five most up-to-date covariant energy density functionals different types, with a non-linear meson coupling, dependent couplings, density-dependent zero-range interactions. Pairing correlations are treated within relativistic Hartree-Bogoliubov (RHB) theory based on an effective separable...
The correlations between global description of the ground state properties (binding energies, charge radii) and nuclear matter state-of-the-art covariant energy density functionals have been studied. It was concluded that strict enforcement constraints on (NMP) defined in Dutra et al. [Phys. Rev. C 90, 055203 (2014)] will not necessarily lead to with good binding energies other excited properties. In addition, it substantially reduce uncertainties predictions neutron-rich systems. turns out...
Theoretical uncertainties in the predictions of inner fission barrier heights superheavy elements have been investigated a systematic way for set state-of-the-art covariant energy density functionals which represent major classes used functional theory. They differ basic model assumptions and fitting protocols. Both statistical quantified where former turn out to be larger. Systematic are substantial their behavior as function proton neutron numbers contains large random component. The...
What are the limits of existence nuclei? highest proton numbers $Z$ at which nuclear landscape and periodic table chemical elements cease to exist? These deceivably simple questions difficult answer especially in region hyperheavy ($Z\geq 126$) nuclei. We present covariant density functional study different aspects stability For first time, we demonstrate three regions spherical nuclei centered around ($Z\sim 138, N\sim 230$), 156, 310$) 174, 410$) expected be reasonably stable against...
Parametric correlations are studied in several classes of covariant density functional theories (CDFTs) using a statistical analysis large parameter hyperspace. In the present manuscript, we investigate such for two specific types models, namely, models with dependent meson exchange and point coupling models. Combined results obtained previously Ref. [1] non-linear model, these indicate that parametric exist all major CDFTs when functionals fitted to ground state properties finite nuclei...
The properties of hyperheavy nuclei and the extension nuclear landscape to are extensively studied within covariant density functional theory. Axial reflection symmetric asymmetric relativistic Hartree-Bogoliubov (RHB) calculations carried out. role triaxiality is triaxial RHB mean field + BCS frameworks. With increasing proton number beyond Z~130 transition from ellipsoidal-like shapes toroidal ones takes place. description latter requires basis which typically significantly larger than one...
A systematic search for axial octupole deformation in the actinides and superheavy nuclei with proton numbers $Z=88-126$ neutron from two-proton drip line up to $N=210$ has been performed covariant density functional theory (DFT) using four state-of-the-art energy functionals representing different model classes. The $Z\sim 96, N\sim 196$ region of have investigated detail uncertainties description their observables quantified. Similar exists also Skyrme DFT microscopic+macroscopic approach...
Statistical errors in ground state observables and single-particle properties of spherical even-even nuclei their propagation to the limits nuclear landscape have been investigated covariant density functional theory (CDFT) for first time. In this study we consider only energy functionals with nonlinear dependency. binding energies neutron skins significantly increase on approaching two-neutron drip line. On contrary, such a trend does not exist statistical charge radii separation energies....
The systematic investigation of the ground state and fission properties even-even actinides superheavy nuclei with $Z=90-120$ from two-proton up to two-neutron drip lines proper assessment theoretical uncertainties has been performed for first time in framework covariant density functional theory (CDFT). These results provide a necessary input r-process modeling heavy and, particular, study recycling. Four state-of-the-art globally tested energy functionals (CEDFs), namely, DD-PC1, DD-ME2,...
In the Ge-Sr mass region, isotopes with neutron number $N \leq 40$ are known to feature rapid shape changes both nucleon and angular momentum. To gain new insights into their structure, inelastic proton scattering experiments in inverse kinematics were performed on rare $^{74,76}$Kr. This work focuses observables related $J^{\pi} = 4^+_1$ states of Kr and, particular, hexadecapole degree freedom. By performing coupled-channels calculations, deformation parameters $\beta_4$ determined for...
We calculate field isotope shifts for nobelium atoms using nuclear charge distributions which come from different models. demonstrate that comparing calculated with experiment can serve as a testing ground theories. It also provides way of extracting parameters distribution beyond RMS radius, e.g. parameter quadrupole deformation $\beta$. argue previous interpretation the measurements in terms $\delta \langle r^2 \rangle$ between $^{252,254}$No isotopes should be amended when is taken into...
Background: The nuclear fission process is a dramatic example of the large-amplitude collective motion in which nucleus undergoes series shape changes before splitting into distinct fragments. This can be represented by pathway many-dimensional space coordinates. Within stationary framework rooted static Schr\"odinger equation, action along determines spontaneous half-lives as well mass and charge distributions fragments.Purpose: We study performance precision various methods to determine...
The properties of toroidal hyperheavy even-even nuclei and the role shell structure are extensively studied within covariant density functional theory. general trends in evolution shapes $Z\approx 130-180$ region nuclear chart established for first time. These stable with respect breathing deformations. most compact fat located 136, N\approx 206$ chart, but thin become dominant increasing proton number on moving towards neutron drip lines. structure, its regularity, supershell gaps as well...
Background: When multiple fission modes coexist in a given nucleus, distinct fragment yield distributions appear. Multimodal has been observed number of fissioning nuclei spanning the nuclear chart, and this phenomenon is expected to affect abundances synthesized during rapid neutron-capture process ($r$-process).Purpose: In study, we generalize previously proposed hybrid model for fission-fragment predict competing estimate resulting distributions. Our framework allows comprehensive...
The current status of the application covariant density functional theory to description actinides and superheavy nuclei is reviewed.The achievements open problems are discussed.
Octupole deformed shapes in neutron-rich actinides and superheavy nuclei as well extremely of the light have been investigated within framework covariant density functional theory. We confirmed presence new region octupole deformation with center around but our calculations do not predict ground states nuclei. As exemplified by study 36Ar, nodal structure wavefunction occupied single-particle orbitals structures allows to understand formation α-clusters very nuclei, suppression...
A slightly prompt critical nuclear reactor would increase the neutron flux exponentially at a high rate causing to become uncontrollable, however due delayed neutrons, it is possible leave in subcritical state as far only neutrons are concerned and also sustain chain reaction when going die out. The delay spectrum of compact core Ghana’s miniature source (MNSR) was studied using Monte Carlo method. 20,484 energy groups combined for all three categories distribution, thermal, slowing down...