Measurement of time - dependent CP - violating asymmetries in B 0 → π + π − and B 0 s → K + K − decays at LHCb

The CP -violating asymmetries in the decay and in the interference between mixing and decay in the B0→ π+π− and B0 s→ K+K− modes are measured using a data sample of pp collisions corresponding to an integrated luminosity of 3 fb−1, collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Flavour tagging is performed using only a subset of the current available taggers. The results are Cπ+π− = −0.24±0.07±0.01, Sπ+π− = −0.68±0.06±0.01, CK+K− = 0.24±0.06±0.02, SK+K− = 0.22 ± 0.06 ± 0.02, and A∆Γ K+K− = −0.75 ± 0.07 ± 0.11, where the first uncertainties are statistical and the second systematic. c © CERN on behalf of the LHCb collaboration, licence CC-BY-4.0. †Conference report prepared for the 9 International Workshop on the CKM Unitarity Triangle (CKM2016), Mumbai, India, 28 November – 2 December 2016. Contact authors: Stefano Perazzini, [email protected] and Vincenzo Maria Vagnoni, [email protected].