Nonleptonic weak decay of Lambda 5He and Lambda 12C.

Hypernuclear lifetime and partial decay-rate measurements made at the Brookhaven National Laboratory Alternating Gradient Synchrotron are reported for $_{\mathrm{\ensuremath{\Lambda}}}^{5}\mathrm{He}$ and $_{\mathrm{\ensuremath{\Lambda}}}^{12}\mathrm{C}$. The mesonic and nonmesonic decays are compared to existing weak-interaction calculations. In particular, the nonmesonic reaction \ensuremath{\Lambda}N\ensuremath{\rightarrow}NN is discussed as an example of a nonleptonic weak process for which calculations have been reported using various effective weak Hamiltonians.