Abstract
We investigate the appearance of di–neutron bound states in pure neutron matter within the Brueckner–Hartree–Fock approach at zero temperature. We consider the Argonne v18 and Paris bare interactions as well as chiral two– and three–nucleon forces. Self–consistent single–particle potentials are calculated by controlling explicitly singularities in the g matrix associated with bound states. Di–neutrons are loosely bound, with binding energies below 1 MeV, but are unambiguously present for Fermi momenta below 1 fm−1 for all interactions. Within the same framework we are able to calculate and characterize di–neutron bound states, obtaining mean radii as high as ∼110 fm. Implications of these findings are presented and discussed.