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The alpha decay half-lives of heavy and superheavy nuclei with Z = 80 - 116 are calculated by a deformed double folding model. To obtain the potential between alpha cluster and daughter nucleus, the R3Y-L1, R3Y-W, R3Y-Z, R3Y-HS, R3Y-NL2 and R3Y-NLSH nucleon-nucleon (NN ) interactions from the relativistic mean field approach are used. Here, the deformation of the daughter nucleus is taken into consideration, while the alpha cluster is assumed to be spherical. The alpha cluster penetration probability has been determined using the Wentzel-Kramers-Brillouin (WKB) semiclassical approximation. By comparison between the calculated half-lives and the experimental ones, it is found that the R3Y-NLSH interaction has the highest accuracy. After establishing the best R3Y parametrizations for the deformed nuclei, they are then used to predict the alpha decay half-lives of unmeasured superheavy nuclei with Z = 120 and 122 . In this case, the Weizsäcker-Skyrme-type nuclear mass model with radial basis corrections (WS-type+RBF) was used to determine the Q α values and preformation factors. The calculations suggest that N = 184 could be a magic number, a deduction that is consistent with previous theoretical calculations. [ABSTRACT FROM AUTHOR]

It is known that pseudospin symmetry plays a crucial role in formation of many physical phenomena. By combining the relativistic mean field theory with the complex momentum representation method, the pseudospin symmetry in the single particle resonant states in the deformed nucleus 1 5 4 Dy is investigated through the energy and width splittings, the quadrupole deformation parameter, the radial density distributions and occupation probabilities of the pseudospin doublets. Near the continuum threshold, the pseudospin symmetry is well reserved in both bound and resonant states. The energy and width splittings of pseudospin doublets in resonant states exhibit correlations with the deformation and quantum numbers. The good pseudospin symmetry is expected with lower pseudo-orbital angular momentum projection Λ ̃ and the main quantum number N. In general, an increase in deformation tends to weaken the quality of the pseudospin symmetry. The understanding of the evolution of the pseudospin doublets in the resonant states has been deepened by studying the pseudospin symmetry in the deformed nuclei. [ABSTRACT FROM AUTHOR]

Pseudospin symmetry (PSS) plays critical roles in the formation of many physical phenomena, and has been studied extensively from spherical nuclei to deformed nuclei. However, there remains an open question about the PSS in resonant states in deformed systems. For the first time, we investigate the PSS in resonant states in deformed nuclei by solving the Dirac equation in the complex-momentum representation for a potential with quadrupole deformation at the first order obtained from relativistic mean-field (RMF) calculations. Taking 170Yb as an example, we explore the PSS in the single-particle resonant states by examining the energies, widths and the density distribution. Compared with the bound states, the pseudospin splittings between the resonant pseudospin doublets are found to be small, and the radial density distributions of pseudospin doublets look very similar, which indicates that the PSS of resonant states is well reserved in deformed nuclei. Moreover, we have comprehensively studied the dependencies of the PSS on nuclear deformations and the shape of potential, which are helpful to recognize the evolution of resonant pseudospin doublets in weakly-bound deformed nuclei and understand their exotic properties.

Photo-nuclear interactions are important for investigating fundamental nuclear physics phenomena. The photo-absorption cross-section energy curve displays a wide resonance called giant dipole resonance (GDR) until 30 MeV. First, spherical and deformed nuclei have been determined by using LogitBoost classifier, and then GDR parameters for deformed nuclei have been estimated by using an artificial neural network (ANN) via Levenberg–Marquardt algorithm which has been selected for the training section. In the last step, 2 3 3 U (γ , n) 2 3 2 U , 2 3 4 U (γ , n) 2 3 3 U , 2 3 5 U (γ , n) 2 3 4 U , 2 3 6 U (γ , n) 2 3 5 U , 2 3 8 U (γ , n) 2 3 7 U reaction cross-sections have been computed by using GDR parameters obtained ANN estimations. The mean square error, root mean square error, and R are evaluated as the best performance of ANN estimates. Photo-neutron cross-section results have been compared with experimental data from the literature. Consequently, it has been found that ANN algorithms can be used to determine the GDR parameters for deformed nuclei in the lack of experimental data of photo-absorption reaction. [ABSTRACT FROM AUTHOR]

In this paper, the spectral statistics of prolatedeformed nuclei are investigated by using random matrix theory. To this aim, we used both available experimental data and also the energy levels of ground, beta, and gamma bands of 51 deformed even-even nuclei, which are determined via partial SU(3) dynamical symmetry limit of interacting boson model. The results verified the ability of the considered models in the restoration of experimental data and also the displacement of beta and gamma energy bands. Also, the dependence of the statistical situation of energy levels is considered to the mass of nuclei, spins, half-lives of the ground state, bands of energy, and different configurations of excited bands of energies. The results suggested obvious differences in the spectral situation of the levels in different rotational bands and also different mass regions. Also, the displacement of levels and the lower energy of state in comparison with level reduce the correlation of levels in spectral statistics.

The location of the neutron drip line, currently known for only the lightest elements, remains a fundamental question in nuclear physics. Its description is a challenge for microscopic nuclear energy density functionals, as it must take into account in a realistic way not only the nuclear potential, but also pairing correlations, deformation effects and coupling to the continuum. The recently developed deformed relativistic Hartree–Bogoliubov theory in continuum (DRHBc) includes all three aforementioned effects in the description of nuclei throughout the nuclear chart. Here, the DRHBc with the successful density functional PC-PK1 is used to investigate whether and how deformation influences the prediction for the neutron drip-line location for even–even nuclei with 8 ≤ Z ≤ 2 0 , where many isotopes are predicted deformed. The results are compared with those based on the spherical relativistic continuum Hartree–Bogoliubov (RCHB) theory and discussed in terms of shape evolution and the variational principle. It is found that the Ne and Ar drip-line nuclei are different after the deformation effect is included. The direction of the change is not necessarily towards an extended drip line, but rather depends on the evolution of the degree of deformation towards the drip line. Deformation effects as well as pairing and continuum effects treated in a consistent way can affect critically the theoretical description of the neutron drip-line location. [ABSTRACT FROM AUTHOR]