We have measured both yields of neutron-proton and neutron-neutron pairs emitted from the non-mesonic weak decay process of Λ 5He and Λ12C hypernuclei produced via the (π+, K+) reaction for the first time. We observed clean back-to-back correlation of the np- and nn-pairs in the coincidence spectra for both hypernuclei. The ratio of those back-to-back pair yields, Nnn/Nnp, must be close to the ratio of neutron- and proton-induced decay widths of the decay, Γn (Λn → nn)/Γp(Λp → np). The obtained ratios for each hypernuclei support recent calculations based on short-range interactions.
ASJC Scopus subject areas
- Nuclear and High Energy Physics