Observation of CP violation in two-body B-(s)(0)-meson decays to charged pions and kaons

The time-dependent CP asymmetries of B0 → π+π− and B0 s → K+K− decays are measured using a data sample of pp collisions corresponding to an integrated luminosity of 1.9fb−1, collected with the LHCb detector at a centre-of-mass energy of 13TeV. The results are Cππ = −0.311±0.045±0.015, Sππ = −0.706±0.042±0.013, CKK = 0.164±0.034±0.014, SKK = 0.123±0.034±0.015, A∆Γ KK =−0.83 ±0.05 ±0.09, where the first uncertainties are statistical and the second systematic. The same data sample is used to measure the time-integrated CP asymmetries of B0 → K + π− and B0 s → K−π+ decays and the results are AB0 CP =−0.0824±0.0033±0.0033, AB0 s CP = 0.236 ±0.013 ±0.011. All results are consistent with earlier measurements. A combination of LHCb measurements provides the first observation of time-dependent CP violation in B0 s decays.