Enhancement factor for two-neutron transfer reactions with a schematic coupled-channels model

Abstract

Probabilities for two-neutron transfer reactions, $P_{2n}$, are often discussed in comparison with the square of the corresponding probabilities for one-neutron transfer process, $(P_{1n}{)}^2$, implicitly assuming that $(P_{1n}{)}^2$ provides the probability of two-neutron transfer reactions in the absence of the pairing correlation. We use a schematic coupled-channels model, in which the transfers are treated as effective inelastic channels, and demonstrate that this model leads to $P_{2n}=(P_{1n}{)}^2/4$, rather than $P_{2n}=(P_{1n}{)}^2$, in the pure sequential limit. We argue that a simple model with spin-up and spin-down neutrons in a single-particle orbital also leads to the same conclusion.

Comments: 4 pages, 2 figures