The influence of the tensor interaction of nucleons on the characteristics of neutron-rich silicon and nickel isotopes was studied in this work. Tensor forces are considered within the framework of the Hartree-Fock approach with the Skyrme interaction. The addition of a tensor component of interaction is shown to improve the description of the splittings between different single-particle states and decrease nucleon-nucleon pairing correlations in silicon and nickel nuclei. Special attention was directed toward the role of isovector tensor forces relevant to the interaction of like nucleons.

In this paper, we determine the location of the neutron drip line for light Lambda hypernuclei. Predictions are made for elements up to carbon within the Skyrme-Hartree-Fock approach. It is shown that Lambda 11Li, Lambda 17,19B and Lambda 22C with unstable nuclear cores are bound whereas Lambda 10,11He and Lambda 14Be are not.

Addition of a Λ-hyperon to non-strange nuclei can lead to an increase in the binding energy and formation of a bound hypernucleus with an unbound nucleon core, effectively leading to the shift of the proton drip line on the hypernuclear chart. The structure of light proton-rich Λ-hypernuclei with 5 ≤ Z ≤ 12 is treated within the Hartree–Fock approach with effective potentials in the Skyrme form. We show that nuclei 8 C and 16 F are most likely can be bound by a hyperon.

In this paper, we propose a method of taking charge symmetry breaking (CSB) in hypernuclei and neutron stars into account within the framework of the Hartree–Fock approach with Skyrme interaction. The parameters of the contribution of Λ N -Skyrme force leading to CSB are derived from the corresponding parameters of the hyperon-nucleon interaction in the meson exchange models. Based on the obtained parameters, the effect of charge symmetry breaking on the hyperon binding energy in carbon hypernuclei is analyzed. The effect of charge symmetry breaking on the characteristics of neutron stars, such as their maximum mass and radii, is considered for the first time.

The structure of light proton-rich Λ-hypernuclei is considered using the Hartree–Fock approach with effective potentials in the Skyrme form. It is argued that the $${}_{\Lambda }^{9}{\text{C}}$$ hypernucleus is bound, unlike its nucleon 8C core. Proton-rich boron, nitrogen, and oxygen hypernuclei with unstable cores are shown to be not bound.

The structure of light $$\Lambda $$ -hypernuclei is studied in the framework of the Hartree–Fock approach with the effective Skyrme potential. This phenomenological approach allows for analysis of hypernuclear properties in relation to both nucleon–nucleon and hyperon–nucleon components of the general baryonic interaction. Hyperon binding energies, as well as radii of nuclear cores are calculated using several Skyrme parametrizations in order to verify the sensitivity of these quantities to the interaction properties.

We determine the location of the proton drip line for light Λ and ΛΛ hypernuclei. While it is already known for 1≤ Z≤ 4 , our main focus is the 5≤ Z≤ 8 range, and further conclusions are drawn for proton-rich Λ hypernuclei up to Z = 20 . Λ binding energies from the Skyrme-Hartree-Fock calculation and the energies of unstable nuclei known experimentally are used. It is shown that ^9_Λ C, ^10_ΛΛ C and ^14_ΛΛ O with unstable nuclear cores are bound whereas ^8_Λ B, ^12_Λ N, ^13_Λ O and ^13_ΛΛ N are not. Boundness of ^9_ΛΛ B remains questionable. Among heavier systems, ^17_Λ F, ^20_Λ Na and ^20_Λ Mg are shown to be the possible candidates for bound hypernuclei.

The structure of light proton-rich Lambda-hypernuclei is addressed in the framework of the HartreeFock approach with effective potentials in the Skyrme form. We argue that the C-9(Lambda) hypernucleus is bound contrary to its nuclear core C-8. Proton-rich boron, nitrogen and oxygen hypernucleus with unstable cores are shown to remain unbound. We check also Lambda Lambda hypernuclei with proton-rich unstable cores.

A study is performed of the spectra of neutron-rich 70–76Ni isotopes in which the main configuration is determined by the filling of subshell 1g9/2. Consideration is given to the dependence of the order of the ground state multiplet (GSM) levels and the splitting of seniority multiplet $$\nu = 4$$ from the position of state $$J = 2\left( {\nu = 2} \right).$$ In several isotopes, an especially low position of this state inverts levels with identical $${{J}^{\pi }}$$ but different seniority $$\nu .$$

Excited states in low-energy spectra in $^{70-76}$Ni are considered. To this end, pairing forces in form of surface delta interaction are employed to account for formation of the ground state multiplet with seniority $\nu = 2$ states. The multiplet splitting is described with mass relations of masses of neighbouring nuclei. Subsequently, seniority model is used to reproduce or predict the states $\nu = 3$ in odd-even isotopes and $\nu = 4$ in even-even isotopes. Correct account of $2_1^+$ state should allow for description of reversed order of states $J = 4$ with $\nu = 2$ and $\nu = 4$ observed in experiment. The results obtained are compared with the structure of similar multiplets in $N=50$ isotones.

We study the consistency of local mass relation approach in its application to prediction of nuclear masses in the region of superheavy elements. Binding energy calculations are carried out for nuclei with [Formula: see text] using formulas for evaluation of residual [Formula: see text]-interaction. The results are found to be in good agreement with the experimental data AME2016. We also make predictions for characteristics of [Formula: see text]-decay in isotopes [Formula: see text]–106, [Formula: see text]–157.

Analysis of various mass formulas related to neutron-proton correlations in atomic nuclei is carried out. Using the example of the N=Z chain it is shown that for self-adjoint nuclei various formulas proposed in literature for estimating the np pairing energy lead to similar results. Significant differences between the calculation methods arise when nuclei with N not equal Z are considered, which allows to reveal the complexity of neutron-proton correlations in different types of atomic nuclei and to make assumptions on the correspondence of the mass relation to the real effect of np pairing. The Shell Model parametrization of the binding energy makes it possible to draw additional conclusions on the structure of mass formulas and their relationship.

GT strength distributions along with beta(-)-decay and electron capture rates are studied for the case of hot nuclei Ni-78 embedded in matter at presupernova conditions. Calculations are performed using the self-consistent Skyrme-RPA approach extended to finite temperatures. Skyrme interaction parametrizations with and without tensor forces are used in order to analyze the role of tensor interaction and thermal effects on weak-interaction rates in hot nuclei.

Different mass relations for estimating neutron–proton correlations are analyzed. The differences between the estimates indicate phenomenologocal distinction between the considered relations. Parametrization with a shell model is used to clarify the structure of different estimates and their correspondence to the real value of np-correlations.

Values of neutron–proton pairing based on mass relations are estimated. It is shown that substantially different formulas for calculating the np-pairing energy in self-conjugate nuclei yield similar results. Comparison of the obtained values and the structure of ground state multiplet spectra shows that mass relations can be used to describe the isovector (T = 1) component of np-pairing to sufficient accuracy, but provides little or no information on isoscalar component T = 0.

The ground state multiplet structure for nuclei over the wide range of mass number A was calculated in δ-approximation and different mass relations for pairing energy were analysed in this work. Correlation between the calculated multiplet structure and experimental data offers a guideline in deciding between mass relations for nucleon pairing.

Various estimates of the even-odd effect of the mass shell of atomic nuclei are considered. Based on the experimental mass values of the Ca, Sn, and Pb isotopes, the dependence of the energy gap on the neutron number is traced and the relationship of this characteristic to the properties of external neutron subshells is shown. In nuclei with closed proton shells, effects directly related to neutron pairing and effects of nucleon shells are discussed.

The pairing interaction of neutrons and protons in calcium isotopes and N = 28 isotones is considered. Ground state multiplets formed by neutrons and protons on the 1f 7/2 subshell with seniority values ν = 2, 3, 4 are investigated. Good agreement between the multiplet splitting value and nucleon pairing energies is shown not only for multiplets with seniorities ν = 2, but for higher seniority values as well.