Recents Results from ATLAS in Beauty and Charm Physics

A wide program of studies in heavy flavour physics is performed with the ATLAS detector, ranging from QCD tests performed on production cross-section and properties of states containing heavy quarks, to searches for new physics in EW processes. Recent and new results will be discussed in the talk, including: Differential production cross-section for $X(3872)$, observed in the decay to $J/\psi\pi^+\pi^-$; Differential production cross-section of $J/\psi$ pairs, separating associated production and multi-parton scattering; Measurement of the width difference in the $B^0 - \bar{B}^0$ system (via the comparison of the decay time distributions to $CP$ and flavour eigenstates); Recent results and Run 2 expectations for FCNC process in the $B^0_s$ systems: rare decays to muon pairs and $CP$ violating phase $\phi_s$ in the decay to $J/\psi\phi$.