Analysis of Λ(1405) production data in the π - p → K 0 πΣ reaction at p π = 1.69 GeV/c.

We have been studying the (Σπ)0 mass distribution based on data from an old Hydrogen Bubble Chamber collected by Thomas et al. concerning the p(π- , K0 )Σπ reaction at pπ = 1.69 GeV/c. In this analysis we investigated the formation of the Λ(1405) state, using the Generalized Optical Theorem and T-matrix operator. We applied a combined transition operator, Tmix , which contains T21 (=TπΣ-KN ) and T22 (= TπΣ-πΣ ) due to the initial channel mixing in the Λ(1405) formation. We also considered a possible mixture of I = 0 and 1 in the wave function, as well as some background of the Σ(1385) population.