We study the one-body momentum distribution at different densities in nuclear
matter, with special emphasis on its components at high momentum. Explicit
calculations for finite neutron-proton asymmetry, based on the ladder
self-consistent Green's function approach, allow us to access the isospin
dependence of momentum distributions and elucidate their role in neutron-rich
systems. Comparisons with the deuteron momentum distribution indicate that a
substantial proportion of high-momentum components are dominated by tensor
correlations. We identify the density dependence of these tensor correlations
in the momentum distributions. Further, we find that high-momentum components
are determined by the density of each sub-species and we provide a new isospin
asymmetry scaling of these components. We use different realistic
nucleon-nucleon interactions to quantify the model dependence of our results.Comment: 14 pages, 7 figures, 1 table. Accepted version in Phys. Rev.
