Models and phenomenology of maximal flavor violation

We consider models of maximal flavor violation, in which a new scalar mediates large $q_3\leftrightarrow q_1$ or $q_3\leftrightarrow q_2$ flavor-changing transitions ($q_i$ is an $i$’th generation quark), while $q_3\leftrightarrow q_3$ transitions are suppressed, e.g., ${\xi }_{31}$, ${\xi }_{13}\sim V_{tb}$ and ${\xi }_{33}\sim V_{td}$, where ${\xi }_{ij}$ are the new scalar couplings to quarks and $V$ is the Cabibbo-Kobayashi-Maskawa matrix. We show that, contrary to the conventional viewpoint, such models are not ruled out by the existing low-energy data on $K^0$, $B^0$ and $D^0$ oscillations and rare $K$ and $B$-decays. We also show that these models of maximal flavor violation can have surprising new signatures at the LHC and the Tevatron.