Next-to-next-to-leading order Skyrme interaction in nuclear matter: Nuclear bulk quantities at second order in perturbation theory

TL;DR

This paper develops a next-to-next-to-leading order Skyrme interaction for nuclear matter, incorporating fourth-order gradient potentials, and evaluates second-order corrections to bulk properties, achieving a good fit to saturation data.

Contribution

It introduces the explicit form of N$^2$LO Skyrme interaction including fourth-order gradients and applies renormalization to compute second-order corrections to nuclear matter properties.

Findings

Good reproduction of nuclear matter saturation curve.

Second-order corrections show strong dependence on Fermi momentum.

Renormalization successfully handles UV divergences.

Abstract

We present the explicit form of the next-to-next-to-leading order (N$^2$LO) Skyrme interaction in momentum space by including the fourth-order gradient potentials to the standard Skyrme interaction. With the N$^2$LO Skyrme interaction, we evaluate the second-order corrections to the nuclear bulk quantities of nuclear matter: equation of state (EoS) of isospin symmetric and pure neutron matter, density-dependent in-medium effective nucleon mass, isospin-asymmetry energy, pressure and incompressibility. These second-order contributions are ultraviolet (UV) divergent due to the zero range character of the interaction and renormalized using the techniques of dimensional regularization (DR) with the minimal subtraction scheme (MS). We adjust the 18 parameters of the interaction by performing a global fit to the nuclear bulk quantities. Besides the too strong dependence $k_F^{12}$ of several second-order corrections, a very good reproduction of a realistic nuclear matter saturation curve with all the nuclear bulk quantities in the density region $0.12<\rho<0.20\;$ fm$^{-3}$ is obtained.