\textbf{Background:} The $^{3}$He($α,γ$)$^{7}$Be reaction plays a crucial role in the proton-proton chain and Big Bang nucleosynthesis, affecting solar neutrino fluxes and primordial element abundances. Experimental data at astrophysical energies remain uncertain due to the extremely low cross sections. \\ \textbf{Purpose:} This work uses a microscopic potential-model approach to construct the $^{3}$He+$α$ potential from the nucleon+$α$ interaction, aiming to describe low-energy elastic scattering and to calculate the astrophysical $S$ factor of the $^{3}$He($α,γ$)$^{7}$Be reaction. \\ \textbf{Method:} The nucleon-nucleus potential is derived from self-consistent Skyrme Hartree-Fock (HF) calculations extended to the continuum. The $^{3}$He+$α$ potential is then obtained by folding the HF potential with the $^{3}$He density. A small number of scaling parameters is constrained by elastic-scattering data.\\ \textbf{Result:} The scaled Skyrme HF potential and folded potential simultaneously reproduce the low-energy $p$+$α$ and $^{3}$He+$α$ $s$-wave phase shifts, respectively. The calculated astrophysical $S$ factor of $^{3}$He($α,γ$)$^{7}$Be shows good agreement with experimental data, yielding the recommended value $S_{34}(0) = 0.610 \pm 0.024$~keV~b. A moderate sensitivity of $S_{34}(0)$ to the choice of projectile density is also observed in the folding procedure. \\ \textbf{Conclusion:} The Skyrme HF-based potential provides a unified and predictive microscopic framework for describing both elastic scattering and radiative capture in light nuclei.
The Skyrme effective interaction, with its multitude of parameterisations, along with its implemen- tation using the static and time-dependent density functional (TDHF) formalism have allowed for a range of microscopic calculations of low-energy heavy-ion collisions. These calculations allow variation of the effective interaction along with an interpretation of the results of this variation informed by a comparison to experimental data. Initial progress in implementing TDHF for heavy-ion collisions necessarily used many approximations in the geometry or the interaction. Over the last decade or…
Within the framework of Skyrme energy-density functional theory, the nucleus-nucleus potential is calculated and potential energy surface is obtained with different effective forces for accurately estimating the formation cross sections of superheavy nuclei in massive fusion reactions. The width and height of the potential pocket are influenced by the Skyrme effective forces SkM, SkM$^{\ast}$, SkP, SIII, Ska and SLy4, which correspond to the different equation of state for the isospin symmetry nuclear matter. It is found that the nucleus-nucleus potential is associated with the collision orien…
The effective Skyrme energy density functionals are widely used in the study of nuclear structure, nuclear reaction and neutron star, but they are less established from the heavy ion collision data. In this work, we find 22 effective Skyrme parameter sets, when incorporated in use the transport model, ImQMD, to describe the heavy ion collision data, such as isospin diffusion data at 35 MeV/u and 50 MeV/u. We use these sets to calculate the neutron skin of $^{208}$Pb based on the restricted density variation method, and obtain the neutron skin of $^{208}$Pb in the range of $δR_{np}=0.18\pm0.04$…
The asymmetry in the neutrino mean free path for the absorption reaction $ν+ n \rightarrow e^{-} + p$, is evaluated within hot neutron matter under a strong magnetic field. We consider densities in the range $0.05 \leq ρ\leq 0.4$ fm$^{-3}$, several temperatures up to 30 MeV and magnetic field strengths from $B=0$ up to $B=10^{18}$~G. Polarized neutron matter is described within the non--relativistic Hartree--Fock model using the LNS Skyrme interaction. The neutrino mean free path has a weak dependence with the temperature and in the strong magnetic field region, it decreases for growing values…
Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals
本文计算了质子数为92 ≤ Z ≤ 104,中子数为144 ≤ N ≤ 156时,氦区原子核基态和激发态的性质。我们使用三种不同的能量密度泛函(EDF)方法,基于协变,Skyrme和Gogny泛函,每个在两个不同的参数集。对奇偶质量交错、准粒子谱和转动惯量所获得的结果进行比较分析,使我们能够确定这些不同模型所特有的单粒子和壳效应,并说明与使用EDF模型相关的可能的系统不确定性
Individual low-energy E1 toroidal and compressional states (TS and CS) produced by the convective nuclear current ${\bf j}_{\rm c}$ were recently predicted for $^{24}$Mg in the framework of quasiparticle random-phase-approximation (QRPA) with Skyrme forces. In the present QRPA study with Skyrme parametrization SLy6, we explore in more detail properties of these states (toroidal and compressional responses, current distributions, and transitions probabilities $B(E1K, 0^+0 \to 1^-K),\; B(E3K, 0^+0 \to 3^-K)$, $B(M2K, 0^+0 \to 2^-K)$ with $K=$0 and 1) and analyze the possibility to discriminate a…
We study the nuclear properties of even-even superheavy $Z$=120 isotopes and $N$=184 isotones with the Skyrme Hartree-Fock-Bogoliubov (HFB)approach. Within this model we examine the deformation energy surfaces and two paths to fission: a reflection-symmetric path with elongated fission fragments (sEF) and a reflection-asymmetric path corresponding to elongated fission fragments (aEF). Furthermore, we explore the energy surfaces in the region of very large oblate deformations with toroidal nuclear density distributions. While the energy surfaces of toroidal $Z$=120 isotopes and $N$=184 isotones…
An extensive study is carried out for the island of stability in the superheavy nuclei of Z=120 and N=164-220 within the effective field theory motivated relativistic mean-field (E-RMF) and the non-relativistic Skyrme-Hartree-Fock (SHF) approaches. The relativistic G3 and IOPB-I and non-relativistic SLy4 and SkMP parameter sets are used for the investigations. Surface properties such as symmetry energy, neutron pressure and the curvature coefficient of symmetry energy are discussed within the coherent density fluctuation model (CDFM) using the Skyrme and the Brückner energy density functionals…
In this work, we systematically study the two-proton($2p$) radioactivity half-lives using the two-potential approach while the nuclear potential is obtained by using Skyrme-Hartree-Fock approach with the Skyrme effective interaction of {SLy8}. For true $2p$ radioactivity($Q_{2p}$ $>$ 0 and $Q_p$ $< $0, where the $Q_p$ and $Q_{2p}$ are the released energy of the one-proton and two-proton radioactivity), the standard deviation between the experimental half-lives and our theoretical calculations is {0.701}. In addition, we extend this model to predict the half-lives of 15 possible $2p$ radioactiv…
The half-lives of proton radioactivity of proton emitters are investigated theoretically by using KDE0v1 Skyrme interaction. The total barrier potential in the proton radioactive nuclei is calculated as the sum of the nuclear, Coulomb and centrifugal contributions. The Hartree-Fock nuclear density distributions is used in calculating the nuclear as well as the Coulomb interaction potentials. The quantum mechanical tunneling probability is calculated within the WKB approximation. These calculations provide reasonable estimates for the observed proton radioactivity lifetimes.
Proton \textit{s}-resonance states of $^{12}$C and $^{14,15}$O within the Skyrme Hartree-Fock mean-field framework
University of Science, Ho Chi Minh City(胡志明市科学大学);Vietnam National University, Ho Chi Minh City(胡志明市越南国立大学);Ho Chi Minh City University of Education(胡志明市教育大学);Institute for Basic Science(基础科学研究院)
We use properties of doubly-magic nuclei, ab-initio calculations of low-density neutron matter, and of neutron stars to constrain the parameters of the Skyrme energy-density functional. We find all of these properties can be reproduced within a constrained family of Skyrme parameters. The maximum mass of a neutron star is found to be sensitive to the neutron effective mass. A value of [$ m^{*}_{\rm n}/m](ρ_0) = 0.60-0.65 $ is required to obtain a maximum neutron star mass of 2.1 solar masses. Using the constrained Skyrme functional with the aforementioned effective mass, the predicted radius f…
We generalize to N2LO Skyrme functionals the semi-classical approach of Grammaticos and Voros in order to calculate the Extended Thomas Fermi expressions of the new densities and currents appearing at the N2LO level. Within a one dimensional symmetric semi infinite nuclear matter model and using a simple Fermi-like density profile, we obtain an easy-to-use formula for the surface energy including the contributions of the central, density-dependent and spin-orbit terms up to $\hbar^2$. Such a formula can be easily used as a first attempt to constrain the surface properties of new N2LO Skyrme pa…
We investigate the spin dependent part of the Skyrme energy-density functional, in particular its impact on the residual particle-hole interaction in self-consistent calculations of excitations. Test cases are the low-energy M1 excitations in $^{208}$Pb treated within the self-consistent random-phase approximation based on the Skyrme energy-density functional. We investigate different parametrizations of the functionals to find out which parameters of the functional have strongest correlations with M1 properties. We explore a simple method of the modification of the spin-related parameters whi…
A systematic analysis of nuclear deformation is made for neutron-rich Ti, Cr, and Fe isotopes to explore the nuclear structure in the island of inversion near N = 40, where strong nuclear deformation is predicted. The nuclear ground states are obtained by the Skyrme Hartree-Fock method in three-dimensional coordinate space, which properly describes any nuclear shape. Three types of Skyrme interactions are employed to generate various deformed states in its isotopic chain. We find that in the island of inversion the occupation of highly elongated intruder orbits induces not only large quadrupol…
The study of CNO cycle involves the examination of the proton radiative capture, or the $(p,γ)$ reactions below 2 MeV. The astrophysical $\mathcal{S}$ factor characterizing the $(p,γ)$ reaction is usually reduced to the electric dipole transition $E1$ from the scattering state to the bound state. In this work, the partial scattering and the single-particle bound wave functions in the reduced matrix element of the transition are obtained from the single self-consistent mean-field potential deduced from the Skyrme Hartree-Fock calculation. The astrophysical $\mathcal{S}$ factors of the $(p,γ)$ r…
The Skyrme model is a low energy effective field theory of strong interactions where nuclei and baryons appear as collective excitations of pionic degrees of freedom. In the last years, there has been a revival of Skyrme's ideas and new related models, some of them with BPS bounds (topological lower energy bounds), have been proposed. It is the aim of this paper to review how they can be applied to the study of neutron stars allowing for a description by means of topological solitons. We will focus on different aspects as the equation of state or the mass-radius relation, where we find that hi…