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

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.