FROM KAON-NUCLEAR INTERACTIONS TO KAON CONDENSATION

An effective chiral Lagrangian in heavy-fermion formalism whose parameters are constrained by kaon-nucleon and kaon-nuclear interactions next to the leading order in chiral expansion is used to describe kaon condensation in dense “neutron star ” matter. The critical density is found to be robust with respect to the parameters of the chiral Lagrangian and comes out to be ρc ∼ (3 −4)ρ0. Once kaon condensation sets in, the system is no longer composed of neutron matter but of nuclear matter. Possible consequences on stellar collapse with the formation of compact “nuclear stars ” or light-mass black holes are pointed out.