Realistic calculations of K ˉ N N , K ˉ N N N , and K ˉ K ˉ N N quasibound states

摘要

Binding energies and widths of three-body K ˉ N N , and of four-body K ˉ N N N and K ˉ K ˉ N N nuclear quasibound states are calculated in the hyperspherical basis, using realistic NN potentials and subthreshold energy dependent chiral K ˉ N interactions. Results of previous K ? p p calculations are reproduced and an upper bound is placed on the binding energy of a K ? d quasibound state. A self-consistent handling of energy dependence is found to restrain binding, keeping the calculated four-body ground-state binding energies to relatively low values of about 30 MeV. The lightest strangeness ?2 particle-stable K ˉ nuclear cluster is most probably K ˉ K ˉ N N . The calculated K ˉ N → π Y conversion widths range from approximately 30 MeV for the K ˉ N N N ground state to approximately 80 MeV for the K ˉ K ˉ N N ground state.