pi. sup 0 decay process of sub. Lambda. sup 12 C and sub. Lambda. sup 11 B hypernuclei

We investigated {pi}{sup 0} decay branching ratios {Gamma}{sub {pi}}{sup 0}/{Gamma} in the weak decay of the {sub {Lambda}}{sup 12}C and {sub {Lambda}}{sup 11}B hypernuclei using the (stopped {ital K}{sup {minus}},{pi}{sup {minus}}) reaction. The branching ratios were estimated to be 0.174{plus minus}0.057(stat){plus minus}0.008(syst) and 0.140{plus minus}0.039(stat){plus minus}0.025(syst) for the {sub {Lambda}}{sup 12}C and {sub {Lambda}}{sup 11}B hypernuclei, respectively. The branching ratios are compared with theoretical calculations and related experimental values. Importance of distortion of pion wave function was found.