Weak decays in heavy nuclei with charge numbers Z=101-109 are studied within a microscopic formalism based on deformed self-consistent Skyrme Hartree-Fock mean-field calculations with pairing correlations. The half-lives of beta+ decay and electron capture are compared with alpha-decay half-lives obtained from phenomenological formulas. Transfermium isotopes of Md, No, Lr, Rf, Db, Sg, Bh, Hs, and Mt that can be produced in the frontier of cold and hot fusion-evaporation channels are considered. Several isotopes are identified whose beta+/EC- and alpha-decay half-lives are comparable. The competition between these decay modes opens the possibility of new pathways towards the islands of stability.
Transfermium nuclei (101$\leq$Z$\leq$110) are investigated thoroughly to describe structural properties viz. deformation, radii, shapes, magicity, etc. as well as their probable decay chains. These properties are explored using relativistic mean-field (RMF) approach and compared with other theories along with available experimental data. Neutron numbers N$=$152 and 162 have come forth with a deformed shell gap whereas N$=$184 is ensured as a spherical magic number. The region with N$>$168 bears witness of the phenomenon of shape transition and shape coexistence for all the considered isotopic …
The even-even Ti isotopic chain, from A = 42 to 70, has been studied within the nuclear shell-model framework by employing an effective Hamiltonian which is derived by way of many-body perturbation theory from a chiral potential with two- and three-body forces, and includes three-body contributions which account for Pauli principle violations in nuclei with more than two valence particles. We consider 40Ca as a closed core and a model space spanned by the neutron and proton 0f1p orbitals with the addition of the 0g9/2 orbital for neutrons. Calculated two-neutron separation energies and excitat…
The density-dependent nuclear symmetry energy is directly related to the isospin asymmetry for finite and infinite nuclear systems. It is critical to determine the coefficients of symmetry energy and its related observables as it holds great importance in different areas of nuclear physics, such as analyzing the structure of ground state exotic nuclei and neutron star study. The ground state bulk properties such as nuclear binding energy, quadrupole deformation, two-neutron separation energy, the differential variation of two-neutron separation energy, and root-mean-square charge radius for Sc…
The newly derived relativistic energy density functional [\textcolor{blue}{ Phys. Rev. C \textbf{103}, 024305 (2021)}], which stems from the effective field theory motivated relativistic mean-field (E-RMF) is employed to establish the appearance of peak/kink in the symmetry energy over the isotopic chain of Pb-nuclei. The coherent density fluctuation model parametrization procedure for finite nuclei is adopted here to obtain the relativistic energy density functional at local density. The relativistic energy density functional from E-RMFT takes precedence over the Brückner energy density funct…
The ground state bulk properties such as binding energy, root-mean-square radius, pairing energy, nuclear density distributions, and single-particle energies are calculated for the isotopic chain of Ca, Sn, Pb, and Z = 120 nuclei. The relativistic mean-field with recently developed G3, IOPB-1, and Relativistic-Hartree-Bogoliubov with density-dependent DD-ME1 and DD-ME2 parameter sets are used in the present analysis. The respective shifts over the isotopic chain for the structural observables and surface property like symmetry energy are also estimated using a three-point method, which is cruc…
The positive-parity states of even-even Xe nuclei are investigated within the framework of modified O(6) limit of the interacting boson model (IBM1). The effective three-body interaction [QQQ] where Q is the IBM O(6) quadrupole operator is introduced to exhibit the triaxiality nature. The shape of nuclear surface is described by the deformation parameters beta, gamma by using the intrinsic coherent state. The potential energy surfaces (PES) of the transition U(5)-Triaxiality-O(6) are calculated and analyzed and the critical phase transition points are identified. For each nucleus a fitting pro…
The temperature dependence of the symmetry energy for isotopic chains of even-even Ni, Sn, and Pb nuclei is investigated in the framework of the local density approximation (LDA). The Skyrme energy density functional with two Skyrme-class effective interactions, SkM* and SLy4, is used in the calculations. The temperature-dependent proton and neutron densities are calculated through the HFBTHO code that solves the nuclear Skyrme-Hartree-Fock-Bogoliubov problem by using the cylindrical transformed deformed harmonic-oscillator basis. In addition, two other density distributions of $^{208}$Pb, nam…
A recent experimental breakthrough identified the last bound neutron-rich nuclei in fluorine and neon isotopes. Based on this finding, we perform a theoretical study of $Z=9, 10, 11, 12$ isotopes in the relativistic mean field (RMF) model. The mean field parameters are assumed from the PK1 parameterization, and the pairing correlation is described by the particle number conservation BCS (FBCS) method recently formulated in the RMF model. We show that the FBCS approach plays an essential role in reproducing experimental results of fluorine and neon isotopes. Furthermore, we predict $^{39}$Na an…
Isotope-Resolved Ba and Xe Yields in Actinide Fission and Correlated Heavy--Light Fragment Systematics
National Centre for Nuclear Research（国家核研究中心）；China Institute of Atomic Energy（中国原子能科学研究院）；Maria Curie-Skłodowska University（玛丽·居里-斯克沃多夫斯卡大学）；Tsinghua University（清华大学）
Sensitivity of Isotopic Fission Yields in Actinides to the Macroscopic Liquid-Drop Model: LSD vs ISOLDA
National Centre for Nuclear Research（国家核研究中心）；Maria Curie-Skłodowska University（玛丽亚·居里-斯克隆多斯卡大学）；China Institute of Atomic Energy（中国原子能科学研究院）；Tsinghua University（清华大学）
Impact of ab initio E1 strength on neutron capture rates along the nickel isotopic chain
Facility for Rare Isotope Beams, Michigan State University（稀有同位素束设施，密歇根州立大学）；Physics Division, Oak Ridge National Laboratory（橡树岭国家实验室物理部）；Department of Physics, Chalmers University of Technology（查尔姆斯理工大学物理系）
Proton inelastic scattering experiments at energy E_p = 200 MeV and a spectrometer scattering angle of 0 degree were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR). Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour can b…
The prediction of single particle level crossing phenomenon between $2p_{3/2}$ and $1f_{5/2}$ orbitals in $Ni$- and $Cu$-isotopic chains by the finite range simple effective interaction without requiring the tensor part is discussed. In this case the experimentally observed crossing could be studied as a function of nuclear matter incompressibility, $K(ρ_0)$. The estimated crossing for the neutron number $N$=46 could be reproduced by the equation of state corresponding to $K(ρ_0)$=240 MeV. However, the observed proton gaps between the $1h_{11/2}$ and $1g_{7/2}$ shells in $Sn$ and $Sb$ isotopic…
Starting from light to superheavy nuclei, we have calculated the effective surface properties such as the symmetry energy, neutron pressure, and symmetry energy curvature using the coherent density fluctuation model. The isotopic chains of O, Ca, Ni, Zr, Sn, Pb, and Z = 120 are considered in the present analysis, which cover nuclei over the whole nuclear chart. The matter density distributions of these nuclei along with the ground state bulk properties are calculated within the spherically symmetric effective field theory motivated relativistic mean field model by using the recently developed …
Isoscalar giant monopole resonance for drip-line and super heavy nuclei in the framework of a relativistic mean field formalism with scaling calculation
In this work, the ground-state properties of the platinum isotopic chain, 160-238Pt, are studied within the covariant density functional theory. The calculations are carried out for a large number of even-even Pt isotopes by using the density-dependent point-coupling and the density dependent meson-exchange effective interactions. All ground-state properties such as the binding energy, separation energy, two-neutron shell gap, rms-radii for neutrons and protons and quadrupole deformation are discussed and compared with available experimental data, and with the predictions of some nuclear model…
The current investigation aims to study the ground-state properties of one of the most interesting isotopic chains in the periodic table, 94-168Sn, from the proton drip line to the neutron drip line by using the covariant density functional theory, which is a modern theoretical tool for the description of nuclear structure phenomena. The physical observables of interest include the binding energy, separation energy, two-neutron shell gap, rms-radii for protons and neutrons, pairing energy and quadrupole deformation. The calculations are performed for a wide range of neutron numbers, starting f…
A unified theoretical model reproducing charge radii of known atomic nuclei plays an essential role in making extrapolations for unknown nuclei. Recently developed new ansatz which phenomenologically takes into account the neutron-proton short-range correlations ($np$-SRCs) can describe the discontinuity properties and odd-even staggering (OES) effect of charge radii along isotopic chains remarkably well. In this work, we further review the modified root-mean-square (rms) charge radii formula in the framework of relativistic mean field (RMF) theory. The charge radii are calculated along variou…
Above-barrier fusion cross-sections for an isotopic chain of oxygen isotopes with A=16-19 incident on a $^{12}$C target are presented. Experimental data are compared with both static and dynamical microscopic calculations. These calculations are unable to explain the $\sim$37\% increase in the average above-barrier fusion cross-section observed for $^{19}$O as compared to $β$-stable oxygen isotopes. This result suggests that for neutron-rich nuclei existing time-dependent Hartree-Fock calculations underpredict the role of dynamics at near-barrier energies. High-quality measurement of above-bar…
Charge radius is one of the most fundamental properties of a nucleus. However, a precise description of the evolution of charge radii along an isotopic chain is highly nontrivial, as reinforced by recent experimental measurements. In this paper, we propose a novel approach which combines a three-parameter formula and a Bayesian neural network. We find that the novel approach can describe the charge radii of all $A\ge40$ and $Z\ge20$ nuclei with a root-mean-square deviation about 0.015 fm. In particular, the charge radii of the calcium isotopic chain are reproduced very well, including the para…
Microscopic description of quadrupole-hexadecapole coupling in radium, thorium, uranium and plutonium isotopes with the Gogny energy density functional
