New results on $B_s$ mixing and CP violation from LHCb

Oscillation effects in the $B_s$ meson system provide a window on physics beyond the Standard Model. The latest results from LHCb on the mass and width differences between the two physical eigenstates, and the CP violating phase measured in the $B_s \to J/\psi \phi$ decay channel are presented. In addition, results of a first study of the CP violating phase in the penguin-dominated $B_s \to \phi \phi$ decays are shown.