Nucore — A system for nuclear structure calculations with cluster-core models

Abstract

One-neutron removal (p,pn) reactions induced by two-neutron Borromean nuclei are studied within a Transfer-to-the-Continuum (TC) reaction framework, which incorporates the three-body character of the incident nucleus. The relative energy distribution of the residual unbound two-body subsystem, which is assumed to retain information on the structure of the original three-body projectile, is computed by evaluating the transition amplitude for different neutron-core final states in the continuum. These transition amplitudes depend on the overlaps between the original three-body ground-state wave function and the two-body continuum states populated in the reaction, thus ensuring a consistent description of the incident and final nuclei. By comparing different 11Li three-body models, it is found that the 11Li(p,pn)10Li relative energy spectrum is very sensitive to the position of the p1/2 and s1/2 states in 10Li and to the partial wave content of these configurations within the 11Li ground-state wave function. The possible presence of a low-lying d5/2 resonance is discussed. The coupling of the single particle configurations with the non-zero spin of the 9Li core, which produces a spin-spin splitting of the states, is also studied. Among the considered models, the best agreement with the available data is obtained with a 11Li model that incorporates the actual spin of the core and contains ∼31% of p1/2-wave content in the n-9Li subsystem, in accord with our previous findings for the 11Li(p,d)10Li transfer reaction, and a near-threshold virtual state.