Microscopic Study of ${}^1{S_0}$ Superfluidity in Dilute Neutron Matter

TL;DR

This paper investigates the superfluidity of dilute neutron matter using a correlated BCS approach, calculating the equation of state and superfluid gap while considering short-range correlations and P-wave effects, with results consistent with other microscopic methods.

Contribution

It introduces a combined correlated BCS method to study ${}^1{S_0}$ superfluidity in dilute neutron matter, including short-range correlations and P-wave contributions.

Findings

The equation of state of neutron matter was calculated using the CBF method.

The ${}^1{S_0}$ superfluid gap was determined with the Argonne V18 potential.

Results are consistent with other microscopic approaches.

Abstract

Singlet $S$-wave superfluidity of dilute neutron matter is studied within the correlated BCS method, which takes into account both pairing and short-range correlations. First, the equation of state (EOS) of normal neutron matter is calculated within the Correlated Basis Function (CBF) method in lowest cluster order using the ${}^1{S_0}$ and ${}^3P$ components of the Argonne $V_{18}$ potential, assuming trial Jastrow-type correlation functions. The ${}^1{S_0}$ superfluid gap is then calculated with the corresponding component of the Argonne $V_{18}$ potential and the optimally determined correlation functions. The dependence of our results on the chosen forms for the correlation functions is studied, and the role of the $P$-wave channel is investigated. Where comparison is meaningful, the values obtained for the ${}^1{S_0}$ gap within this simplified scheme are consistent with the results of similar and more elaborate microscopic methods.