The Λ(1405) N → YN transition in the nuclear medium for non-mesonic absorption of a [formula omitted] in nuclei

Abstract

The non-mesonic transition Λ (1405) N → Y N is investigated as one of the essential processes for the non-mesonic absorption of a K ¯ in nuclei. Using a one-meson exchange model in the calculation of the transition, we find that the non-mesonic transition ratio Γ Λ N / Γ Σ N depends strongly on the ratio of the Λ (1405) ( Λ * ) couplings to K ¯ N and πΣ. Especially, a larger Λ * - K ¯ N coupling leads to enhancement of the transition to Λ N. Using the chiral unitary model for the description of the Λ * , we obtain Γ Λ N / Γ Σ 0 N ≈ 1.2 which is almost independent of the nucleon density, and find the total non-mesonic decay width of the Λ * in uniform nuclear matter to be 22 MeV at the normal density.