Neutron pairing with medium polarization beyond the Landau approximation

TL;DR

This paper investigates how medium polarization effects influence neutron superfluid transition temperatures, showing that the full RPA provides a more accurate description than the Landau approximation at higher densities.

Contribution

It demonstrates that the Landau approximation is inadequate at higher densities and that the full RPA reveals stronger screening effects in dilute neutron matter.

Findings

Landau approximation is sufficient below 0.002 fm$^{-3}$ density.

Full RPA predicts stronger screening effects at higher densities.

Revisiting neutron pairing with advanced polarization models improves understanding of superfluidity.

Abstract

We revisit the long-standing problem of the superfluid transition temperature $T_c$ in dilute neutron matter. It is well known that $T_c$ is strongly affected by medium polarization effects (screening) which modify the pairing interaction in the medium. We study these effects within the random-phase approximation (RPA). It turns out that the widely used Landau approximation is sufficient only at densities below about 0.002 fm$^{-3}$. At higher densities, the full RPA leads to stronger screening than the Landau approximation.