Measurement of CP violation in the B⁰_s system

Studies of CP violation play a key role in the search for physics beyond the Standard Model. In the B⁰_s system these mainly consist of measurements of mixing-induced CP violation, which arises from the interference between the B⁰_s−⁰_s mixing process and the subsequent decay. This report focusses on two such asymmetry measurements recently published by the LHCb collaboration. The first analysis presents the measurement of a CP violating phase in B⁰_s → φφ, which is found to be φ_φφ = −0.17±0.15(stat)±0.03(syst)rad. The second provides an updated measurement of the B⁰_s−⁰_s mixing phase φ_s using the B⁰_s → J/ψπ⁺π⁻ channel. It yields φ_s = 0.070 ± 0.068 (stat) ± 0.008 (syst) rad. Both results are consistent with the Standard Model expectations and no indication for direct CP violation was found in either decay mode.