Medium polarization in asymmetric nuclear matter

TL;DR

This paper investigates how core polarization affects the effective nuclear interaction in asymmetric nuclear matter, revealing a transition from attraction to repulsion in certain states and discussing implications for neutron star superfluidity.

Contribution

It provides a detailed analysis of the isospin-dependent core polarization effects on nuclear interactions in asymmetric matter, including the crossover behavior in spin singlet states.

Findings

Crossover from attractive to repulsive interaction in spin singlet state with increasing isospin asymmetry.

Induced interaction in spin triplet state remains repulsive across conditions.

Results have implications for understanding neutron star superfluid phases.

Abstract

The influence of the core polarization on the effective nuclear interaction of asymmetric nuclear matter is calculated in the framework of the induced interaction theory. The strong isospin dependence of the density and spin density fluctuations is studied along with the interplay between the neutron and proton core polarizations. Moving from symmetric nuclear matter to pure neutron matter the crossover of the induced interaction from attractive to repulsive in the spin singlet state is determined as a function of the isospin imbalance.The density range in which it occurs is also determined. For the spin triplet state the induced interaction turns out to be always repulsive. The implications of the results for the neutron star superfluid phases are shortly discussed.