New Physics in B and K Decays

Flavour physics offers interesting probes for the exploration of the Standard Model and the search for new physics. In these lectures, we focus on B- and K-meson decays, introduce the concept of low-energy effective Hamiltonians to describe them theoretically, and discuss how physics beyond the Standard Model may generically affect the roadmap of quark-flavour physics. We address then both the implications of the B-factory data for the B_d -> J/psi K_S channel and the prospects of B_s -> J/psi phi modes for hadron colliders, and discuss how the Standard Model may be challenged through B_d -> phi K_S. Finally, as an example of a systematic flavour strategy to search for new physics, we analyze puzzling patterns in the B -> pi pi, pi K data and study their interplay with rare K and B decays.