2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42730I estimate the SU(3) flavour symmetry breaking in the ratio of penguin-to-tree ratios of the decays B_s\to K^+ K^- and B_d\toπ^+π^-, given an assumption on the flavour symmetry breaking of the hadronic input parameters. The decay amplitudes are calculated in QCD factorization. Implications for the determination of gamma are discussed.3 pages, LaTeX, Talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConfC0304052)High Energy Physics - Phenomenologytext