2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185248We 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 $\La_c$ decay we obtain a reasonable agreement with experiment. For the $\La_b$ semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry of about 20%.Revised version. Title changed. 11 pages (RevTex), 4 PS figuresHigh Energy Physics - Phenomenologytext