Self-consistent dynamical mean-field investigation of exotic structures in isospin-asymmetric nuclear matter

Abstract

The exotic structures expected in the outermost layer of neutron stars are investigated in a new approach. It is based on the DYnamical WAvelets in Nuclei (DYWAN) model of nuclear collisions. This microscopic dynamical approach is an Extended Time-Dependent Hartree–Fock description based on a wavelet representation. The model addresses the dynamical exploration of complex nuclear structures, beyond the Wigner–Seitz (WS) approximation and without any assumption on their final shapes. The present study focuses on exotic phases of cold matter evidenced dynamically at sub-saturation densities, currently within a pure mean field framework, before tackling the effects of the multi-particle correlations in a forthcoming study. Starting from inhomogeneous initial conditions provided by nuclei located on an initial crystalline lattice, the exotic structures result from a dynamical self-consistent treatment where, in principle, the nuclear system can freely self-organize, modify the lattice structure or even break the lattice and the initial matter distribution symmetries. In this work nuclei are initially slightly excited with low-lying collective modes. The system can then explore geometrical configurations with similar energies, without being trapped in the vicinity of a local minimum. In this quantum framework, different effects are analyzed, among them the sensitivity to the equation of state and to the proton fraction.