Narrow Results

The properties of even–even Zr and Pb isotopes in the ground state are studied up to the neutron drip-lines on the basis of the Hartree–Fock method with Skyrme forces allowing for deformation (DHF). The DHF calculations with Ska forces predict the existence of stability peninsula (or island) around ¹⁵²Zr. On the example of Zr isotopes it is shown that adding neutrons to an already unstable nucleus with neutron excess can restore the stability. It is demonstrated that extremely neutron-rich Pb isotopes for 222≤A≤230 have abnormally large deformation parameters of proton and neutron density distributions. The existence of ^266–288Pb stable against one-neutron emission is also predicted.

The possibility to produce superheavy elements in the course of low-yield nuclear explosions is analyzed within a simple kinetic model which includes neutron capture, γ-emission, fission and particle evaporation from excited nuclei. We have calculated average numbers of absorbed neutrons as well as mass distributions of U and Cm nuclei exposed to an impulsive neutron flux as functions of its duration. It is demonstrated that detectable amounts of heavy nuclei absorbing from 20 to 60 neutrons may be produced in this process. According to an optimistic scenario, after multiple β-decay such nuclei may reach the long-living elements of the predicted "island of stability".

Using HF+BCS method with Skyrme forces we analyze the neutron drip line. It is shown that the drip line may form stability peninsulas. These peninsulas locate along fixed neutron numbers on the nuclear chart, which correspond to magic and new magic numbers, and are the same for all Skyrme forces. It is found that the size of the peninsulas is sensitive to the choice of Skyrme forces and the most extended peninsulas appear with the SkI2 set.

We studied the charge radius ($r_c$), neutron radius ($r_n$), and neutron skin-thickness ($\mathrm{\Delta }r=r_n-r_p$) over a chain of isotopes from C to Zr with the stable region to the neutron drip line. Theoretical calculations are done with axially deformed self-consistent relativistic mean-field theory (RMF) and effective nonlinear NL3 and NL3* interactions. The theoretically estimated values are compared with available experimental data and a reasonable agreement is noted. We additionally assessed the two-neutron separation energy ($S_{2n}$) to mark the drip line nuclei of the considered isotopic series. In the reference of $S_{2n}$, neutron magicity is also discussed. The calculated neutron radii are compared with empirical estimation made by $r=r_0{N}^{1/3}$ to examine the abnormal trend of the radius for neutron drip line nuclei. In view to guide the long tails, the density distribution for some skin candidates is analyzed. Finally, neutron skin thickness is observed for the whole considered isotopic series.

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 $8\le Z\le 20$, 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.

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

Using HF+BCS method with Skyrme forces we analyze the neutron drip line. It is shown that the drip line may form stability peninsulas. These peninsulas locate along fixed neutron numbers on the nuclear chart, which correspond to magic and new magic numbers and are the same for all Skyrme forces. It is found that the size of the peninsulas is sensitive to the choice of Skyrme forces and the most extended peninsulas appear with the SkI2 set.