Neutron drip line in the deformed relativistic Hartree–Bogoliubov theory in continuum: Oxygen to Calcium

Abstract

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 [Formula: see text], 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.

Study on deformed halo nucleus $^{31}$Ne with Glauber model based on microscopic self-consistent structures

“…A measurement in 2009 of the large Coulomb breakup cross section of 31 Ne bombarding Pb and C targets, which showed a large soft E1 excitation for the ground state, was interpreted as a p-wave halo [7] -making 31 Ne the heaviest halo nucleus found at that time. Subsequent measurements of the interaction cross section found an enhancement of 12% above those of neighboring Neon isotopes, which suggested an s-or p-wave halo in 31 Ne [8].…”

“…In 2014, we utilized the analytical continuation of the coupling constant (ACCC) method, based on a relativistic mean field (RMF) structure theory with the Bardeen-Cooper-Schrieffer (BCS) pairing approximation -the RAB model [12] -to calculate neutron-and matter-radii, one-neutron separation energies, p-and f -wave energies and occupation probabilities, and neutron densities for single-particle resonant orbitals in 27−31 Ne. These results were analyzed for characteristics of neutron halo formation in 31 Ne due to a competition of the occupation for unbound resonant orbitals and the pairing correlations. Based on a radius increase from 30 Ne to 31 Ne that is much larger than the increase from 29 Ne to 30 Ne, and a simultaneous decrease in the neutron separation energy, a p-wave 1n halo structure was predicted for 31 Ne.…”

Microscopic study of higher-order deformation effects on the ground states of superheavy nuclei around $^{270}$Hs

“…In addition, we would like to mention that the calculations performed in this work can also be done with the deformation relativistic Hartree-Bogoliubov (DRHBc) theory [78][79][80][81][82][83][84], in which the scalar potential and densities are expanded in terms of the Legendre polynomials but the time consuming of the DRHBc theory is much heavier than that for MDC-RMF. Very recently, the influence of higher-order deformation on possible bound nuclei beyond the drip line has been investigated in the transfermium region from No (Z = 102) to Ds (Z = 110) by using the DRHBc theory [85] and a nuclear mass table with the DRHBc theory is in progress [86][87][88][89].…”

Shape coexistence and neutron skin thickness of Pb isotopes by the deformed relativistic Hartree-Bogoliubov theory in continuum

“…This extension is mainly due to the deformation and the continuum states as discussed in Ref. [26,35].…”

“…[17,18] and recently extended [19] with point-coupling density functionals. This theory is proved to be capable for a nice description of the nuclear mass with highly predictive power [20,21] and successfully applied to some nuclei [24][25][26], which followed the previous relativistic continuum Hartree-Bogoliubov (RCHB) approach calculated in coordinate space [27,28] by explicitly including the deformation in a Dirac Woods-Saxon basis [29]. In this work, we introduce briefly the basic formalism of the DRHBc theory, which was succinctly summarized in Refs.…”