The kaon optical potential modified by Θ^+ Pentaquark excitation

Abstract

We study the kaon nuclear optical potential including the effect of the Θ^+ pentaquark in a self-consistent approach, starting from an extension of the Juelich meson-exchange potential as bare kaon-nucleon interaction. Significant differences between a fully self-consistent calculation and the low-density Tρapproximation are observed. Whereas te influence of the KN -> Θ^+ absorption process is found to be negligible, due to the small Θ^+ KN coupling, the two-nucleon mechanism (KNN -> Θ^+ N), estimated from the two-meson coupling of the pentaquark, provides the necessary additional kaon absorption to reconcile with data the systematically low theoretical K^+ nucleus reaction cross sections.