2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41362We show that threshold resummation of the end-point logarithms in inclusive $b$-hadron decays leads to a Sudakov factor, which introduces $1/m_b$ power corrections through infrared renormalons. These power corrections are strong enough to account for the observed semileptonic branching ratio, charm yield, and lifetime ratios by breaking the local quark-hadron duality.4 pages, no figures, uses Revtex4; title changed, typos correctedHigh Energy Physics - Phenomenologytext