Near threshold production of the pseudoscalar mesons at the COSY-11 facility

We summarise measurements of the COSY-11 collaboration concerning the excitation functions of the near threshold pseudoscalar meson production in the proton-proton interaction. The results are discussed in the context of the meson-nucleon and hyperon-nucleon interactions. We conclude that the η-proton interaction is significantly stronger than the η′-proton interaction. Similarly, we found that the hyperon Λ interacts with the nucleon considerably stronger than the hyperon Σ, and that the interaction of K−-proton is much stronger than this of the K-proton. PACS. 14.40.-n Mesons – 14.40.Aq π, K, and η mesons – 13.60.Le Meson production