Kaon-condensed hypernuclei as highly dense self-bound objects

The structure of $K^-$-condensed hypernuclei, which may be produced in the laboratory in strangeness-conserving processes, is investigated using an effective chiral Lagrangian for the kaon-baryon interaction, combined with a nonrelativistic baryon-baryon interaction model. It is shown that a large number of negative strangeness is needed for the formation of highly dense and deeply bound state with kaon condensates and that part of the strangeness should be carried by hyperons mixed in the nucleus. The properties of kaon-condensed hypernuclei such as the ground state energy and particle composition are discussed. Such a self-bound object has a long lifetime and may decay only through weak interaction processes. Comparison with other possible nuclear states is also made, such as kaon-condensed nuclei without mixing of hyperons and noncondensed multistrange hypernuclei. Implications of kaon-condensed hypernuclei for experiments are mentioned.