Weak decay of hypernuclei

Two important modes of hypernuclear weak decays are the π-mesic decay and the nonmesic decay. The suppression of the π-mesic decay due to the pauli principle reflects not only the precise forms of the Λ and nucleon S. P. wf's but also the short-range and tensor force correlations existing in the realistic hypernuclear wf. we have investigated this feature of the π-mesic decay by combining the DDHF approach and the diagrammatic representation of the correlation effects. We could regard the π-mesic decay as a tool to see real occupation probabilities of the hole orbits. The nonmesic decays of sub(Λ)4H, sub(Λ)4He and sub(Λ)5He have been studied with the π and rho exchange model. The nonmesic decay interaction induced by the π - rho exchange is of tensor dominant character. (Mori, K.)