Persistent contribution of unbound quasiparticles to the pair correlation in continuum Skyrme-Hartree-Fock-Bogoliubov approach

TL;DR

This paper studies how unbound quasiparticles influence neutron pair correlations in nuclei near the drip-line using continuum Skyrme-Hartree-Fock-Bogoliubov theory, revealing persistent contributions from broad resonances.

Contribution

It demonstrates that broad unbound quasiparticle resonances continue to significantly contribute to pairing correlations despite their large widths.

Findings

Broad quasiparticle resonances persist and contribute to pairing.

Continuum coupling enhances the role of unbound states in pairing.

Pairing properties are significantly affected by unbound quasiparticle states.

Abstract

The neutron pair correlation in nuclei near the neutron drip-line is investigated using the selfconsistent continuum Skyrme-Hartree-Fock-Bogoliubov theory formulated with the coordinate-space Green's function technique. Numerical analysis is performed for even-even N = 86 isotones in the Mo-Sn region, where the 3p3/2 and 3p1/2 orbits lying near the Fermi energy are either weakly bound or unbound. The quasiparticle states originating from the l = 1 orbits form resonances with large widths, which are due to the low barrier height and the strong continuum coupling caused by the pair potential. Analyzing in detail the pairing properties and roles of the quasiparticle resonances, we found that the l = 1 broad quasiparticle resonances persist to feel the pair potential and contribute to the pair correlation even when their widths are comparable with the resonance energy.