STUDY OF LAMBDA-N-]NN PROCESS IN POLARIZED HE-5(LAMBDA)

Strangeness changing weak hyperon nucleon interaction is studied by ob serving the weak nonmesonic decay (NM-decay) of Lambda hypernuclei (La mbda N --> NN). Observation of its branching ratios gave spin-isospin structure of the NM-decay. Recently we carried out the experiment to o bserve asymmetry of protons from the weak NM-decay of the polarized He -5(Lambda) hypernucleus. The asymmetry is due to interference between amplitudes with different parities. It is shown that asymmetry paramet er elucidates the dominant part of the NM-decay mechanism.