Equation of state of low--density neutron matter and the $^1S_0$ pairing gap

TL;DR

This paper investigates the equation of state and superfluid properties of low-density neutron matter, focusing on the $^1S_0$ pairing gap, using advanced quantum Monte Carlo methods with realistic interactions.

Contribution

It provides new calculations of the neutron matter equation of state and pairing gap at low densities using state-of-the-art many-body techniques and realistic nuclear interactions.

Findings

Ground state energy and pairing gap calculated for low-density neutron matter.

Neutron matter exhibits superfluidity in the studied density range.

Structural properties like pair distribution functions analyzed.

Abstract

We report results of the equation of state of neutron matter in the low--density regime, where the Fermi wave vector ranges from $0.4 fm^{-1} \leq k_F \leq 1.0 fm^{-1}$. Neutron matter in this regime is superfluid because of the strong and attractive interaction in the $^1S_0$ channel. The properties of this superfluid matter are calculated starting from a realistic Hamiltonian that contains modern two-- and three--body interactions. The ground state energy and the $^1S_0$ superfluid energy gap are calculated using the Auxiliary Field Diffusion Monte Carlo method. We study the structure of the ground state by looking at pair distribution functions as well as the Cooper-pair wave function used in the calculations.