Rare decays and other electroweak b-physics Measurements at ATLAS and CMS

In b quark decay the tree-level process with W exchange is hardly modified by new physics beyond the standard model; the search for new physics hints can be done exploiting the sensitivity of some processes to loop diagrams. Such processes include rare FCNC decays, whose branching ratio or angular distributions could be modified by the presence of new degrees of freedom in the loops. Another process where new physics could show itself is $B^0_s$ meson mixing, where the CP violation phase is predicted by SM to be very small and the observation of a significant violation would indicate the presence of new processes.