Comment on enhancements in the reaction K-d → π-Λp

Using the dispersion-theoretic approach to the two-channel final-state interaction model, we investigate the Λp invariant-mass distribution in the reaction K-d → π-Λp observed by Cline et al. The effects of YN final-state interactions are estimated with a phenomenological two-channel N/D solution given by Takahashi et al. Each of two enhancements appearing is explained as follows: One just above the ΛN threshold is due to the effect of ΛN scattering in the two-channel final-state interaction. The other just below the ΣN threshold is the combined effect due to the deuteron dynamics and either the 3S1 Λp resonance or the sharp cusp phenomenon by the ΣΛ conversion in the 3S1 state. It is pointed out that the P-wave contribution has to be carefully estimated for the enhancement just above the ΛN threshold. (author)