CHIRAL UNITARY STUDY OF THE _{pp → p}ΛK⁺ AND _{pp → p}Σ⁰K⁺ PROCESSES

The _{pp → p}ΛK⁺ and _{pp → p}Σ⁰K⁺ reactions near threshold are studied using the chiral unitary model. The single-pion and single-kaon exchanges are taken into account as well as the final state interactions of nucleon-hyperon, K-hyperon and K-nucleon systems. We calculate the total cross section of the _{pp → p}ΛK⁺ reaction which is consistent with the experimental data. We also calculate the total cross section of the _{pp → p}Σ⁰K⁺ reaction. Our result can explain the experimental observed strong suppression of Σ⁰ production compared to Λ production at the same excess energy.