Scaling Limit Analysis of Borromean Halos

Abstract

The analysis of the core recoil momentum distribution of neutron-rich isotopes of light exotic nuclei is performed within a model of halo nuclei described by a core and two neutrons dominated by the s-wave channel. We adopt the renormalized three-body model with a zero-range force, which accounts for the Efimov physics. This model is applicable to nuclei with large two-neutron halos compared to the core size, and a neutron–core scattering length larger than the interaction range. The halo wave function in momentum space is obtained by using as inputs the two-neutron separation energy and the energies of the singlet neutron–neutron and neutron–core virtual states. Within our model, we obtain the momentum probability densities for the Borromean exotic nuclei Lithium-11 ((Formula presented.) Li), Berylium-14 ((Formula presented.) Be) and Carbon-22 ((Formula presented.) C). A fair reproduction of the experimental data was obtained in the case of the core recoil momentum distribution of (Formula presented.) Li and (Formula presented.) Be, without free parameters. By extending the model to (Formula presented.) C, the combined analysis of the core momentum distribution and matter radius suggest (i) a (Formula presented.) C virtual state well below 1 MeV; (ii) an overestimation of the extracted matter (Formula presented.) C radius; and (iii) a two-neutron separation energy between 100 and 400 keV.