New Physics searches with Heavy Flavour observables at ATLAS

New and recent results from the ATLAS programme of studies in electroweak physics with open beauty are presented. Flavour-Changing-Neutral-Current (FCNC) processes are sensitive to New Physics contributions, in particular through additional electroweak loop amplitudes. The angular analysis of the decay of $B_d \to K^* \mu \mu$ for a number of angular coefficients are measured as a function of the invariant mass squared of the di-muon system for data collected by the ATLAS experiment at a centre-of-mass energy $\sqrt{s}$ = 8 TeV. A comparison is made to theoretical predictions, including for the observable $P^\prime_5$, for which there has been recent tension between theory and experiments.