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A systematic investigation of superheavy nuclei in the isotopic chains of proton numbers Z=106, 114, 120, and 126 together with isotonic chains of neutron numbers N=162, 172, and 184 is presented in the theoretical framework of relativistic mean-field density functionals based on density-dependent meson-nucleon couplings. Ground-state properties, including binding energy, shape, deformation, density profile, and radius, are estimated to provide compelling evidence of magicity in these even-even nuclei, aligning with the concept of the 'island of stability.' The analysis reveals central depletion in the charge density, indicating a bubble-like structure, primarily attributed to the substantial repulsive Coulomb field and the influence of higher l -states. A thorough examination of potential decay modes, employing various semi-empirical formulas, is presented. The probable α -decay chains are evaluated, demonstrating excellent agreement with available experimental data. [ABSTRACT FROM AUTHOR]

Applications of configuration-mixing methods for nuclei near the proton and neutron drip lines are discussed. A short review of magic numbers is presented. Prospects for advances in the regions of four new "outposts" are highlighted: 28 O, 42 Si, 60 Ca and 78 Ni. Topics include shell gaps, single-particle properties, islands of inversion, collectivity, neutron decay, neutron halos, two-proton decay, effective charge, and quenching in knockout reactions. [ABSTRACT FROM AUTHOR]

In nuclear theory, there is always a quest for possible extensions of the nuclear landscape and extending our knowledge to the limits of nuclear existence. In this study, we examine the stability and structural properties of a wide range of nuclei in super- and ultra-heavy region in a phenomenological semi-microscopic approach. we calculated the shell correlation energy, residual pairing correction energy, two-nucleon separation energy and two-nucleon energy gap for 3670 even–even nuclei along β -stability line and two-neutron driplines in the ranges 7 0 ≤ Z ≤ 2 7 4 with 8 0 ≤ N ≤ 5 4 8 and 7 0 ≤ Z ≤ 2 1 2 with 1 2 6 ≤ N ≤ 5 4 8 , respectively. To assure reliability and confidence of the new results in the ultra-heavy region, we extended the search space to include heavy and super-heavy nuclei. We report 83 double magic nuclei and address the predominance of proton and neutron magic numbers. Our calculations reproduced known results on nuclear magicity and present strong evidences on islands of stability and magic numbers in super- and ultra-heavy regions. We also address shifts in nuclear magicity along the nuclear landscape close to the β -stability line and close to the neutron rich regions. [ABSTRACT FROM AUTHOR]

Abstract: For at least 60years, scientists have known that certain numbers of protons or neutrons in nuclei formed closed shells of some kind, producing additional stability to nuclei that possess these properties. The most stable nuclei, or nuclei exhibiting enhanced stability, are called doubly magic. Only recently, Lucas has explained that the magic numbers are really composites of several sub shells filling, rather than being single shells. In addition, his theory leads to a conclusion that protons and neutrons fill sub shells in a different way. This is because the protons are charged particles, and by Coulomb repulsion they try to get as far away from each other as possible, hence tending to occupy the outer regions of nuclei. Neutrons, being uncharged but possibly polarizable, tend to occupy both outer and inner shells and to possibly increase the number in an outer shell when the nuclei are heavy in a similar way to electrons filling in inner shells in the Lanthanide and Actinide series. Using these ideas, and following a simple modification of Lucas’ geometrical packing scheme, individual candidates for new magic proton numbers and new magic neutron numbers have been identified. Amazingly, these new magic numbers correspond to the experimentally identified superheavy element distribution to a very large extent, and even correspond to magic numbers suggested using very sophisticated theoretical physics methods and computations. As an added bonus, the newly suggested magic numbers correspond to the long lived Thorium and Uranium isotopes, and to the Fermium isotopes, which may help explain the shape of the Peninsula of Heavy isotopes. They also suggest going back to reassess somewhat lighter isotopes to see if some magic effects have been missed. [ABSTRACT FROM AUTHOR]

Abstract: The decay energy spectrum for neutron unbound states in 24O (, ) has been observed for the first time. The resonance energy of the lowest lying state, interpreted as the level, has been observed at a decay energy above 600 keV. The resulting excitation energy of the level above 4.7 MeV, supplies strong evidence that 24O is a doubly magic nucleus. The data is also consistent with the presence of a second excited state around 5.33 MeV which can be interpreted as the level. [Copyright &y& Elsevier]

The significant features of exchange symmetry are displayed by simple systems such as two identical, spinless fermions in a one-dimensional well with infinite walls. The conclusion is that the maxima of probability of the antisymmetrized wave function of these two fermions lie at the same positions as if a repulsive force (of unknown nature) was applied between these two fermions. This conclusion is combined with the solution of a mathematical problem dealing with the equilibrium of identical repulsive particles (of one or two kinds) on one or more spheres like neutrons and protons on nuclear shells. Such particles are at equilibrium only for specific numbers of particles and, in addition, if these particles lie on the vertices of regular polyhedra or their derivative polyhedra. Finally, this result leads to a pictorial representation of the structure of all closed shell nuclei. This representation could be used as a laboratory for determining nuclear properties and corresponding wave functions. [ABSTRACT FROM AUTHOR]

Abstract: Recently, Lucas has explained that the magic numbers are really composites of several sub shells filling, rather than being single shells. In addition, his theory leads to the conclusion that protons and neutrons fill sub shells differently, because the protons tend to occupy outer shells first, while neutrons tend to occupy both outer and inner shells. Using a simple modification of Lucas’ geometrical packing scheme, new magic proton and neutron numbers were postulated for the superheavy nuclei, which matched the island of stability distribution to a large extent. These magic numbers were also tested against some nuclei in the peninsula of isotopes, and found to be relevant. Now, in consideration of a suggestion made many years ago by Linus Pauling, new magic numbers between 50 and 82 are postulated in the continent of isotopes, and compared to experimental data. These new numbers have strong support among the three elements considered by Pauling, namely Cadmium, Tin and Tellurium, and the results suggest that the range of isotopes found, their stability, and their lifetimes are strongly affected by the new magic numbers. In addition, if 58 nucleons are taken to be magic, then the double hump fission distribution for heavy isotopes may be explained semi-quantitatively. [Copyright &y& Elsevier]

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z = 6 spin-orbit shell gap towards the neutron dripline. To do so, we employed N A (p,2p) C A − 1 quasi-free scattering reactions to measure the proton component of the 2 1 + state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1 p 1 / 2 − 1 p 3 / 2 spin-orbit splitting, at variance to recent claims for a prevalent Z = 6 magic number towards the neutron dripline. [ABSTRACT FROM AUTHOR]