Correlated two-pion exchange in the hyperon-nucleon system

A dynamical model for the correlated two-pino-exchange contribution to the interaction between hyperons (Λ, Σ) and nucleons is constructed, in the scalar-isoscalar channel. Parameterized in terms of conventional σ-exchange, the resulting coupling strengths, gσΛΛgσNN = 0.33 and gσΣΣgσNN = 0.28, are quite different from those used in present hyperon-nucleon potential models. Implications for the existence of the H-dibaryon are discussed.