Realistic calculations of Kbar-N-N, Kbar-N-N-N, and Kbar-Kbar-N-N quasibound states

TL;DR

This paper performs realistic calculations of binding energies and widths for various Kbar-nuclear quasibound states using hyperspherical basis and chiral interactions, providing insights into their stability and decay properties.

Contribution

It introduces a self-consistent energy-dependent approach to calculate quasibound states, refining previous models and estimating properties of light strangeness -2 clusters.

Findings

Binding energies are limited to about 30 MeV for four-body states.

KbarKbarNN is likely the lightest stable strangeness -2 cluster.

Decay widths range from 30 to 80 MeV for different states.

Abstract

Binding energies and widths of three-body KbarNN, and of four-body KbarNNN and KbarKbarNN nuclear quasibound states are calculated in the hyperspherical basis, using realistic NN potentials and subthreshold energy dependent chiral KbarN interactions. Results of previous K^-pp 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 Kbar nuclear cluster is most probably KbarKbarNN. The calculated Kbar N -> pi Y conversion widths range from approximately 30 MeV for the KbarNNN ground state to approximately 80 MeV for the KbarKbarNN ground state.