Effects of three-baryon forces on kaon condensation in hyperon-mixed matter

TL;DR

This paper investigates how three-baryon forces influence kaon condensation in hyperon-rich matter, showing that these forces can stiffen the equation of state to align with observations of massive neutron stars.

Contribution

It introduces the combined effects of three-baryon forces and relativistic baryon interactions on kaon condensation in hyperon-mixed matter, providing new insights into neutron star equations of state.

Findings

Three-baryon forces counteract softening of the EOS due to kaon condensation.

The resulting EOS can support neutron stars with masses consistent with recent observations.

Relativistic effects and three-baryon forces together stiffen the matter at high densities.

Abstract

Possibility of kaon-condensed phase in hyperon-mixed matter is considered on the basis of chiral symmetry for kaon-baryon and kaon-kaon interactions, being combined with the relativistic mean-field theory for two-body baryon interaction. In addition, universal three-baryon repulsive force in the string-junction model and phenomenological three-nucleon attractive force are introduced. It is shown that softening of the equation of state stemming from both kaon condensation and mixing of hyperons is compensated with the repulsive effect of the three-baryon force and the relativistic effect for two-body baryon-baryon interaction. The latter effect reflects the density-dependence of scalar and vector meson mean-fields, which is constrained by the contribution of the attractive three-nucleon force to the binding energy at saturation density. The kaon-condensed phase in hyperon-mixed matter becomes stiff enough to be consistent with recent observations of massive neutron stars.