Computation of QCD processes is always hard. The use of lattice QCD is limited to low-lying hadronic (often single-particle) states, so that only exclusive processes can be computed. Perturbation theory, plus operator product expansion, is used for high-energy processes for which the final states are not specified, or summed over all possible states, i.e. inclusive processes. There are...
I will provide a review of the theoretical basis of predictions for exclusive b -> s mu mu processes within the Standard Model and beyond. I will then discuss how present phenomenological studies of these decays are carried out, what improvements are forthcoming, and how the results should be interpreted.