Rare B decays at LHC

This paper gives an overview of the latest performance studies of LHCb, ATLAS, and CMS in rare-B sector. Flavour Changing Neutral Currents involves b→d or b→s transitions occurring only from loop-level in the Standard Model. They consequently provide an excellent probe of effects of New Physics. Within the Standard Model, these decays are sensitive to the CKM matrix elements |Vts| and |Vtd|. Some of these channels, like B→K*γ, have already been measured at B-factories. However, due to a very large bb¯ production, the LHC will play a leading role in rare B-decays studies. Very promising sectors, like B→K*μμ or B→ρμμ, will be extensively studied at LHC. Other rare channels, like B→μμ or Bs→ϕγ, could be observed for the first time at the LHC.