Low energy reactions K-p→Σ⁰π⁰, Λπ⁰, K⁰n and the strangeness S=-1 hyperons

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A combined study of the reactions K-p→ Σ⁰π⁰, Λπ⁰ and K⁰n at low energies is carried out with a chiral quark-model approach. Good descriptions of the experimental observations are obtained. The roles of the low-lying strangeness S=-1 hyperon resonances in these processes are carefully analyzed. We find that: (i) In the K-p→ Σ⁰π⁰ process, both Λ(1405)S₀₁ and Λ(1520)D₀₃ play dominant roles. Significant contributions of Λ(1670)S₀₁ and Λ(1690)D₀₃ could be seen around their threshold; (ii) In the K-p→ Λπ⁰ process, some obvious evidence of Σ(1775)D₁₅ and Σ(1750)S₁₁ could be found. Some hints of Σ(1620)S₁₁ might exist in the reaction as well. Σ(1750)S₁₁ and Σ(1620)S₁₁ should correspond to the representations [70,⁴8]S₁₁ and [70,²8]S₁₁, respectively; (iii) In the K-p→ K⁰n process, the dominant resonances are Λ(1405) and Λ(1520). Some evidence of Λ(1690)D₀₃, Σ(1670)D₁₃ and Σ(1775)D₁₅ could be seen as well. A weak coupling of Λ(1670)S₀₁ to KN should be needed in the reactions K-p→ Σ⁰π⁰ and K⁰n. Furthermore, by analyzing these reactions, we also find that the u-, t-channel backgrounds and s-channel Born term play crucial roles in the reactions.