2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/217759We present theoretical and experimental preparations for an indirect search for new physics using the rare decay $\bar B_d \to \bar K^* l^+ l^-$. We design new observables with very small theoretical uncertainties and good experimental resolution.Based on invited talks given at the Second Workshop on Theory, Phenomenology and Experiments in Heavy Flavour Physics, 16th-19th of June, Capri, Italy and at the Fifth International Workshop on the CKM Unitarity, Triangle, 9th-13th of September, Rome, Italy; 8 pages, 12 figures, latex, changes: typos in (8) and (15) correctedHigh Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext