Introduction

In the almost fifty years since the phenomenon of superconductivity was brought into nuclear structure,[1,2,3] our knowledge of the nature of pairing correlations in nuclei is still unsatisfactory and many fundamental questions remain (see Refs.[4,5,6] and papers quoted therein). For instance, some components of the pairing interaction are believed to be induced, like in solid-state superconductors,[7] some are directly rooted in the nucleon-nucleon force. In practical calculations based on effective interactions, one considers various pairing parametrizations. The resulting pairing fields have a strong influence on most low-energy properties of the nuclei[8] and the nuclear large-amplitude collective motion. Indeed, by increasing configuration mixing and reducing the magnitude of symmetry-breaking effects, pairing tends to make the nuclear collective motion more adiabatic,[9] Therefore, when aiming at a quantitative understanding of fission properties of heavy and superheavy elements, it is important to have the pairing channel under control.

The purpose of this study is to compare different pairing schemes that are currently used in the Skyrme-Hartree-Fock+BCS (SHF+BCS) model to describe nuclear superfluidity. Within this framework, we compare the seniority paring force and state-dependent $\delta$-interaction (referred to as SHF+BCS(G) and SHF+BCS($\delta$), respectively). As in our previous paper,[10] we focus here on the fission properties of even-even isotones with $N$=184; namely, we discuss the total binding energies, mass hexadecapole moments, and pairing gaps calculated along the static fission paths.