A study of the Λπ−pd final state produced in K−-meson interactions at rest in helium

Abstract

Results are presented of a bubble chamber study of K−-meson interactions at rest in helium leading to the Λπ−pd final state. It is found that (75±1)% of this final state results from the two-step mechanism of internal Σ-Λ conversion via processes such as\(K^ - {\mathcal{N}} \to \Sigma \pi \) followed by\(\Sigma {\mathcal{N}} \to \Lambda {\mathcal{N}}\). The experimental results are compared to the predictions of a double-impulse model, in which a contribution has been included from a Σ-Λ conversion process involving two nucleons in order to reproduce the baryon momentum spectra. The model is capable of explaining the features of the invariant-mass distributions of the finalstate particles without invoking resonance production.