Mesonic and non-mesonic decay widths of C-12(Lambda)

Results are reported on the precise measurement of the lifetime and the wea k-decay branching ratios with charged particle(pi(-) and proton) emission f rom C-12(Lambda) formed via C-12(pi(+), K+) reaction. The pi(-) mesonic dec ay width is consistent with the calculations including the pion wave functi on distortion effect. We observed large contribution of the neutron-stimula ted decay widths, Gamma(Lambda + n --> n + n), in the non-mesonic weak deca y, which cannot be explained by the current theoretical calculations.