Pairing effects on vorticity of incident neutron current at quasiparticle resonance energies in $n$-$A$ elastic scattering

TL;DR

This paper investigates how pairing effects influence the vorticity and circulation of incident neutron currents at quasiparticle resonances in neutron-nucleus elastic scattering, revealing distinct behaviors for particle and hole types.

Contribution

It provides a detailed numerical analysis of pairing effects on neutron current vorticity using Hartree-Fock-Bogoliubov theory, highlighting differences between particle and hole quasiparticle resonances.

Findings

Pairing reduces neutron flux entry in h-type resonances.

Pairing decreases circulation below resonance energy in p-type resonances.

Pairing increases circulation above resonance energy in p-type resonances.

Abstract

In this study, we analyzed how the incident neutron current is affected by the pairing effect in the neutron-nucleus scattering described within the framework of Hartree-Fock-Bogoliubov theory by performing numerical calculations in terms of current, vorticity, and circulation of the incident neutron current. We found that the pairing effect on the incident neutron flux is completely different between particle-type and hole-type quasiparticle resonances. In the case of h-type quasiparticle resonance, the pairing acts to prevent the neutron flux from entering the nucleus, reducing circulation. In the case of p-type quasiparticle resonance, pairing acts to reduce circulation at energies lower than the resonance energy, but at energies higher than the resonance energy, the effect of pairing on the neutron flux is reversed and, conversely, circulation is increased.