Ground state normalization in the nonmesonic weak decay of 12ΛC hypernucleus within a nuclear matter formalism

The nonmesonic weak decay width of 12ΛC hypernucleus has been evaluated within a nuclear matter formalism, using the local density approximation. In addition to the one-body induced decay (ΛN→nN), it has been also considered the two-body induced decay (ΛNN→nNN). This second decay is originated from ground state correlations, where a renormalization procedure to ensure a ground state normalized to one has been implemented. Our results show that the plain addition of the two-body induced decay implies a lost in the ground state-norm, which adds ∼38% of spurious strength to the nonmesonic weak decay width. Within our scheme, it is possible to reproduce the most recent data for the nonmesonic weak decay width of 12ΛC.