2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48356We review the perturbative QCD formalism for exclusive heavy meson decays, concentrating on the three-scale factorization theorem for nonleptonic processes. The formalism is then extended to the radiative decay $B\to K^*γ$, which occurs through penguin diagrams. It is observed that the contributions from the operators other than the penguin one $b\to sγ$ are not negligible. From the best fit to the experimental data of the branching ratio ${\cal B}(B\to K^*γ)$, we extract the $B$ meson wave function, which possesses a sharp peak in the region with a small momentum fraction.numerical outcomes are revisedHigh Energy Physics - Phenomenologytext