Triplet pairing in neutron matter in a comprehensive diagrammatic approach

TL;DR

This paper employs a comprehensive diagrammatic approach to calculate superfluid gaps in neutron matter, revealing how many-body correlations significantly alter pairing interactions and gap magnitudes.

Contribution

It introduces a large-scale summation of Feynman diagrams, including parquet and non-parquet diagrams, to accurately compute pairing interactions in neutron matter.

Findings

Many-body correlations suppress the $^3P_2-^3F_2$ gap.

They enhance the $^3P_0$ gap.

Spin-orbit interaction is strongly reduced.

Abstract

We apply a large-scale summation of Feynman diagrams, including the class of parquet diagrams plus important contributions outside the parquet class, for calculating effective pairing interactions and subsequently the superfluid gap in P-wave pairing in neutron matter. We use realistic nucleon-nucleon interactions of the $v_8$ type and perform calculations up to a Fermi momentum of 1.8 fm$^{-1}$. We find that many-body correlations lead to a strong reduction of the spin-orbit interaction, and, therefore, to a radical suppression of the $^3P_2-^3F_2$ gap and an enhancement of the $^3P_0$ gap.