Strange baryonic matter from chiral effective Lagrangians Original Research Article

We investigate the existence of bound states of baryons in a kaon condensate using chiral mean field theory based on an effective SU(3)L × SU(3)R chiral Lagrangian with next to leading order terms (n = 2, 3, 4). We search for infinite baryon number solutions, namely “strange baryonic matter”, using a Thomas-Fermi and the lowest order Hartree approximations. For simplicity we study a pure K0-condensate and only neutrons, the lightest baryons in that condensate. We find solutions with neutron number densities, ϱn ≳ 3.5ϱ0, where ϱ0 is the infinite nuclear matter density. This is consistent with the estimate of the onset of a K-condensate at ϱn ≅ 2−4ϱ0. We show that the binding energies, Eb, grow with ϱn and for ϱn < 7ϱ0 (at ϱn ≳ 7ϱ0 perturbative expansion is lost) we find Eb < 150 MeV (Eb < 70 MeV for ϱn < 5ϱ0) even in the most favorable cases. These binding energies may be too low for this type of matter to appear and persist in the early Universe.