The odd-even differences in stability peninsula for $106 \leqslant Z \leqslant 112$ region with the deformed relativistic Hartree-Bogoliubov theory in continuum

TL;DR

This paper uses the deformed relativistic Hartree-Bogoliubov theory in continuum to predict a stability peninsula for superheavy nuclei with Z between 106 and 112, highlighting odd-even differences and deformation effects.

Contribution

It demonstrates the predictive power of the DRHBc theory for superheavy nuclei and elucidates the role of deformation and pairing effects in nuclear stability near the drip line.

Findings

93 bound nuclei predicted beyond the drip line in the Z=106-112 region

Significant odd-even differences in bound nuclei and separation energies

Quadrupole deformation is the main contributor to stability peninsula formation

Abstract

The predictive power of the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) with density functional PC-PK1 is demonstrated for superheavy region ($101 \leqslant Z \leqslant 120$) by comparing with available experimental and evaluated data in the AME2020. The DRHBc theory predicts 93 bound nuclei beyond the drip line $N = 258$ in the region of $106 \leqslant Z \leqslant 112$, which form a stability peninsula. The odd-even differences between odd-$N$ and even-$N$ nuclei are remarkable in the stability peninsula; the number of bound odd-$N$ nuclei is less than that of bound even-$N$ nuclei, and the one-neutron separation energy of an odd-$N$ nucleus is smaller than those of its neighboring even-$N$ nuclei due to the blocking effect. The deformation effect is indispensable for the reentrant stability beyond the drip line by significantly affecting the structure of single-particle levels around the Fermi energy. The interplay between deformation and pairing effects affects the position where the odd-$N$ nucleus becomes bound in the stability peninsula. By examining the deformation effect at different orders, it is found that quadrupole deformation makes leading contribution to the appearance of stability peninsula and the effects of hexadecapole and hexacontatetrapole deformations are nonnegligible.