QCD sum rules calculation of heavy Λ semileptonic decay

Abstract We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic Λ c decay we obtain a reasonable agreement with experiment. For the Λ b semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry of about 20%.