Physics potential of the decays Bs;d -> J/psi eta and Bs -> J/psi phi in the ATLAS experiment at the LHC

The CP asymmetry predicted by the Standard Model in the decay modes Bs;d -> J/psi eta and Bs -> J/psi phi is very small, and the observation of a sizeable e ect would be a clear indication of new physics beyond the Standard Model. Contrary to the final state J/psi phi, the former final state is a CP eigenstate, and therefore complex angular distribution analyses are not necessary for the asymmetry measurement. In this paper, the approaches for the study of these two decay channels are presented.