Searches for new physics with heavy flavour at ATLAS

The FCNC processes are sensitive of NP contributions, in particular through additional electroweak loop amplitudes. The angular analysis of the decay of $B^0\to K^{*0}\mu^+\mu^-$ is presented. A number of angular coefficients are measured as a function of the invariant mass squared of the di-muon system for data collected by ATLAS at $\sqrt{s} = 8$ TeV. Comparison is made to theoretical predictions, including for the observable $P_5^\prime$, for which there has been recent tension between theory and experiment. ATLAS results on the study of the $B^0_s\to \mu^+\mu^-$ rare decay is also presented.