Rare heavy flavor decays at ATLAS and CMS

Two general purpose LHC-experiments, ATLAS and CMS, in addition to their main search/discovery program will perform a study of rare beauty hadron decays. An enormous cross-section for beauty production at the LHC, efficient triggers and precise measurements in the tracking systems provide a possibility to measure branching ratios of rare B decays down to ∼10−9. Such a sensitivity allows us to test New Physics contributions in rare B decays. In ATLAS and CMS a manifestation of the New Physics could be seen after the first couple of years, even before the direct observations of physics phenomena beyond the Standard Model.