Pairing enhancement in a two-neutron transfer process through the continuum

TL;DR

This paper investigates how continuum states and pairing correlations enhance two-neutron transfer reactions, especially in weakly-bound systems like helium isotopes, highlighting the importance of continuum modeling.

Contribution

It demonstrates the critical role of continuum states in enhancing two-neutron transfer reactions through pairing correlations in weakly-bound nuclei.

Findings

Continuum states cause significant enhancement in transfer reactions.

Proper modeling of the continuum is crucial for accurate predictions.

Resonant states in the continuum contribute to constructive interference.

Abstract

Enhancement, due to constructive interference through the many possible reaction channels, occurs in two-neutron transfer reactions from a bound system $A$ to a weakly-bound system ($A$+2), whenever the intermediate system is unbound and consists of a continuum with a resonant state. We elucidate this phenomenon in the case of $^6$He, modeled as two neutrons in the orbitals of an intermediate $^5$He nucleus, comparing the realistic case of an unbound ($A$+1) system with an artificially bound case. A properly modeled continuum in these calculations is found to be crucial and leads to significant enhancement due to pairing correlations.