  The nonmesonic weak decay width of $^{12}_{\Lambda}C$ hypernucleus has been
evaluated within a nuclear matter formalism, using the local density
approximation. In addition to the one-body induced decay $(\Lambda N \to n N)$,
it has been also considered the two-body induced decay $(\Lambda NN \to n N
N)$. 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 $\sim 38%$ of
spurious intensity to the nonmesonic weak decay width. By an adequate selection
of the $\Lambda N$-transition potential, our result for the nonmesonic weak
decay width of $^{12}_{\Lambda}C$ is 0.956, in good agreement with the most
recent data.
