Abstract
In the present work, we have studied the alpha-like clusters (
8
Be,
12
C,
16
O,
20
Ne, and
24
Mg) decay half-lives in the trans-tin region for (
106–116
Xe,
108–120
Ba,
114–126
Ce, and
...118–128
Nd) and in transition metal region for (
156–166
Hf,
158–172
W,
160–174
Os,
166–180
Pt, and
170–182
Hg) nuclei. These half-lives have been calculated using the shape parametrization model of cluster decay in conjunction with the axially deformed relativistic mean-field model with the NL3
*
parameter set. They are also compared with the half-lives computed using the latest empirical relations, namely universal decay law and the scaling law was given by Horoi
et al
. It has been observed that in the trans-tin region the minimum cluster decay half-lives are found at nearly doubly magic or doubly magic daughter
100
Sn nucleus (
N
d
= 50,
N
d
is the neutron number of the daughter nucleus) and in transition metal region at
N
d
= 82, which is a magic number. The Geiger–Nuttal plots of half-lives showing
Q
dependence for different alpha-like clusters from various cluster radioactive emitters are found to vary linearly.
In the present work, we have studied the structural properties, alpha and clusters (8Be, 12C, 16O, 20Ne, and 24Mg) decay half-lives for the Th, U, and Pu isotopes using the well-known Relativistic ...Mean-Field (RMF) theory with NL3* parameter set. We calculate the binding energy per nucleon, root-mean-square (rms) radii, two-neutron separation energies (S2n), and other observables. The results are in good agreement with the finite-range droplet model (FRDM) and experimental data. Using the calculated mass defect results from these calculations, the Effective liquid drop model (ELDM) has been used to determine alpha and cluster decay half-lives. The half-lives calculations are also carried out by using the latest empirical relations, namely Universal Decay Law (UDL), TM, VS, and the Scaling Law was given by Horoi et al., and their comparisons with ELDM results are found to be in good agreement. In the plots for log10T1/2 versus the neutron number of the daughter nucleus Nd in the corresponding decay, the half-life is found to have a minimum for the decay leading to nearly doubly magic or doubly magic daughter 208Pb nucleus (Nd=126). The Geiger-Nuttal plots for different clusters from various cluster radioactive (CR) emitters have been studied and they clearly show a linear behavior.
In the present work, we have performed systematic studies of nuclear reactions of various light and medium mass nuclei (He, Li, Be, B, C, Ca, Ni, Zr and Sn isotopes) on
12
C and proton targets mainly ...at high energies using Glauber model and a comparison of the results with available experimental data is made. The microscopic nuclear densities needed for these calculations have been obtained using relativistic Hartree–Bogoliubov formalism. In addition, other ground-state bulk properties are also calculated and compared with the available experimental data. It has been observed that the results obtained using the relativistic framework with the density-dependent meson exchange (DD-ME2) parameter set are in better agreement with the experimental data than with the density-dependent point coupling (DD-PC1) results. Also, we have seen that the total reaction cross-section increases with the increase of the projectile mass. The differential elastic scattering cross-section results obtained with both parameter sets are almost identical at low scattering angles and compare well with the experimental data. However, at higher scattering angles, they show significant differences from the experimental data.
The nuclear structure systematics of superheavy nuclei lying at the extremes, namely Z=116, 118, 120, and 122, and their α-decay half-lives are investigated using relativistic mean-field (RMF) model, ...relativistic Hartree-Bogoliubov (RHB) theory, and nonrelativistic Hartree-Fock-Bogoliubov (HFB) method. In this study, we predict the half-life for unobserved elements consistently with the study of experimentally observed even-even superheavy nuclei with Z=106-118. The structural properties of considered nuclei are studied within the same theoretical models with different nuclear effective interactions. The calculated mass the defect has been used as input in the shape parametrization model of alpha decay to determine the α-decay half-lives. These calculations suggest significant uncertainty due to the sharp sensitivity of half-lives on the Qα values, although the ground-state observables agree fairly well.
Magnetic form factors from odd-A spherical and deformed nuclei corresponding to elastic electron scattering are calculated in the plane-wave Born approximation. The nuclear structure of the target is ...described within a deformed self-consistent mean-field calculation with effective interactions of Skyrme type and pairing correlations in the BCS approximation. We focus our attention to stable nuclei where experimental information is available. It is shown that the deformed formalism improves the agreement with experiment in deformed nuclei, while reproducing equally well spherical nuclei by taking properly the spherical limit of the deformed model. Effects of the collective rotation and nucleon-nucleon correlations are also studied. These results demonstrate the ability of the method to address electron scattering from unstable nuclei to be measured in future experiments on electron-ion beam colliders.
The neutron skin of nuclei is an important fundamental property, but its accurate measurement faces many challenges. Inspired by charge symmetry of nuclear forces, the neutron skin of a neutron-rich ...nucleus is related to the difference between the charge radii of the corresponding mirror nuclei. We investigate this relation within the framework of the Hartree-Fock-Bogoliubov method with Skyrme interactions. Predictions for proton skins are also made for several mirror pairs in the middle mass range. For the first time the correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated simultaneously for nuclei and their corresponding mirror partners. As an example, the Ni isotopic chain with mass number A=48−60 is considered. These quantities are calculated within the coherent density fluctuation model using Brueckner and Skyrme energy-density functionals for isospin asymmetric nuclear matter with two Skyrme-type effective interactions, SkM* and SLy4. Results are also presented for the symmetry energy as a function of A for a family of mirror pairs from selected chains of nuclei with Z=20, N=14, and N=50. The evolution curves show a similar behavior crossing at the N=Z nucleus in each chain and a smooth growing deviation when N≠Z starts. Comparison of our results for the radii and skins with those from the calculations based on high-precision chiral forces is made.
.
The structure of the exotic
8
B nucleus is studied by means of elastic scattering, as well as its breakup on nuclear targets. We present microscopic calculations of the optical potentials (OPs) and ...cross sections of elastic scattering of
8
B on
12
C,
58
Ni, and
208
Pb targets at energies
20
<
E
<
170
MeV. The density distributions of
8
B obtained within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the potentials. The real part of the hybrid OP is calculated using the folding model with the direct and exchange terms included, while the imaginary part is obtained on the base of the high-energy approximation (HEA) and also taken to be equal to the microscopic real part of the OP. In this model the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the elastic scattering experimental data. A dependence of their values on the model density of
8
B is found. In addition, the cluster model, in which
8
B consists of a
p
-halo and the
7
Be core, is applied to calculate the breakup cross sections of the
8
B nucleus on
9
Be,
12
C, and
197
Au targets, as well as momentum distributions of
7
Be fragments, and a comparison with the existing experimental data is made.
We investigate the temperature dependence of the volume and surface components of the nuclear symmetry energy (NSE) and their ratio in the framework of the local density approximation. The results of ...these quantities for finite nuclei are obtained within the coherent density fluctuation model (CDFM). The CDFM weight function is obtained using the temperature-dependent proton and neutron densities calculated through the HFBTHO code that solves the nuclear Skyrme-Hartree-Fock-Bogoliubov problem by using the cylindrical transformed deformed harmonic-oscillator basis. We present and discuss the values of the volume and surface contributions to the NSE and their ratio obtained for the Ni, Sn, and Pb isotopic chains around double-magic 78Ni, 132Sn, and 208Pb nuclei. The results for the T-dependence of the considered quantities are compared with estimations made previously for zero temperature showing the behavior of the NSE components and their ratio, as well as with the available experimental data. The sensitivity of the results on various forms of the density dependence of the symmetry energy is studied. We confirm the existence of "kinks" of these quantities as functions of the mass number at T = 0 MeV for the double closed-shell nuclei 78Ni and 132Sn and the lack of "kinks" for the Pb isotopes, as well as the disappearance of these kinks as the temperature increases.
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