2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41554We describe a new method for obtaining the CP phase alpha via measurements of B_{d,s} -> K(*) Kbar(*) decays. This method is particularly appropriate for hadron colliders since some of the branching ratios are small [O(10^{-6})], and since B_s decays are involved. By comparing the value of alpha extracted from this method with that obtained in B -> pi pi or B -> rho pi decays, one can detect the presence of new physics in the b -> d penguin amplitude. The method does require theoretical input, but model calculations suggest that the theoretical uncertainty is at most 5%, and might well be even smaller. These estimates can be tested experimentally. The method is therefore quite clean.6 pages, LaTeX, no figures. Talk given by David London at Flavor Physics and CP Violation (FPCP), Philadelphia, PA, USA, May 2002High Energy Physics - Phenomenologytext