2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42767In this talk I give an introduction to methods used to give a model independent description of QCD effects in B-decays. I discuss three useful expansions: mb/mW << 1 for the electroweak Hamiltonian, LambdaQCD/mb << 1 for Heavy Quark Effective theory, and LambdaQCD/Q << 1 for the Soft-Collinear Effective Theory where Q ~ mb is the large energy of light final state hadrons. I discuss predictions that can be made with each expansion.10 pages, talk given at the XXXVIIIth Rencontres de Moriond, QCD and Hadronic InteractionsHigh Energy Physics - Phenomenologytext