Microscopic 8-quark study of the antikaon-nucleon-nucleon systems

Abstract

We study the possibility of binding eight quarks in a molecular hadronic system composed of two nucleons and an antikaon, with the quantum numbers of a hexaquark flavor, in particular, with strangeness $\ensuremath{-}1$, isospin $1/2$, parity -, baryonic number 2, and two possible spins, 0 or 1. We discuss the possible production of this hadron in the experiments which are presently investigating hot topics like the ${\ensuremath{\Theta}}^{+}$ pentaquark or the ${K}^{\ensuremath{-}}$ deeply bound in nuclei. The ${K}^{\ensuremath{-}}\ifmmode\bullet\else\textbullet\fi{}N$ interactions and the coupling to other channels are computed microscopically from a confining and chiral invariant quark model resulting in local plus separable Gaussian potentials. The $N\ifmmode\bullet\else\textbullet\fi{}N$ interactions used here are the state of the art Nijmegen potentials. The binding energy and the decay rate of the ${K}^{\ensuremath{-}}\ifmmode\bullet\else\textbullet\fi{}N$ and ${K}^{\ensuremath{-}}\ifmmode\bullet\else\textbullet\fi{}N\ifmmode\bullet\else\textbullet\fi{}N$ systems are computed with configuration space variational methods.