CP Violation and Rare B decays at ATLAS

The primary goal of ATLAS experiment at LHC is to search for the Higgs boson and supersymmetry. However, other physics sectors like CP violation and rare B-decays, can be explored. The full proper-time and angular analyses allow several parameters of physics interest to be investigated using the $B_s^0\to J/\psi\phi$ decays. In the $B_s$ sector measurements, special emphasis is made on the $\Delta M_s$. ATLAS will be able to reach $\Delta M_s$-regions that are today covered by the fit combining all existing data. By investigating rare decays of beauty mesons and baryons, ATLAS will be capable of performing sensitive tests of physics phenomena beyond the Standard Model. The effort concentrate especially on those rare B decays that can be identified already at the first and second trigger level.