Isovector splitting of nucleon effective mass in infinite nuclear matter

The effective mass of neutrons (m∗ n ) and protons (m∗ p ) in asymmetric nuclear matter are different because of the asymmetry in the nucleon-nucleon interaction between like (n−n or p − p) and unlike (n − p) nucleon pairs. It is, however, not well constrained suggestive of the fact that the isovector part of the nuclear interaction is poorly known. Starting from an well-accepted set of empirical nuclear constants, we try to determine this mass difference (m∗ n−m∗ p ) in a nearly interaction-independent framework and relate it to nuclear symmetry elements like the nuclear symmetry energy and its density derivatives that have profound implications in terrestrial physics, astrophysics and cosmology.