Summary
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.
Riassunto
Si presentano i risultati di uno studio con camera a bolle delle interazioni di mesoni K− a riposo nell’elio che portano a stati finali Λπ−pd. Si è trovato che il (75±1)% di questo stato finale risulta dal meccanismo a due stadi della conversione (Σ-Λ) interna tramite i processi come\(K^ - \mathcal{N} \to \Sigma \pi \) seguiti da\(\Sigma {\mathcal{N}} \to \Lambda {\mathcal{N}}\). Si confrontano i risultati sperimentali con le predizioni di un modello a impulso doppio in cui è stato incluso un contributo da un processo di conversione (Σ-Λ) che coinvolge due nucleoni, in modo da riprodurre lo spettro degli impulsi del barione. Il modello è in grado di spiegare le caratteristiche delle distribuzioni di massa invariante delle particelle dello stato finale senza richiedere la produzione di risonanze.
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Erkend ondorzoeker I.I.K.W., presently at CERN.
Chercheur agréé à l'IISN, Belgique.
Traduzione a cura della Redazione.
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Roosen, R., Vander Velde-Wilquet, C., Wickens, J.H. et al. A study of the Λπ−pd final state produced in K−-meson interactions at rest in helium. Nuov Cim A 49, 217–234 (1979). https://doi.org/10.1007/BF02896724
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DOI: https://doi.org/10.1007/BF02896724