ATLAS measurement of CP Violation with Beauty mesons

A measurement of the B^0_s -> J/\psi \phi parameters using 80.5 fb^{-1} of integrated luminosity collected with the ATLAS detector from 13 TeV proton-proton collisions at the LHC is presented. The measured parameters include the CP-violating phase \phi_s, the width difference \Delta\Gamma_s between the B^0_s meson mass eigenstates and the average decay width \Gamma_s. Careful analysis of systematic uncertainties was performed. The values measured for the physical parameters are combined with those from 19.2 fb^{-1} of 7 TeV and 8 TeV data, leading to the following: \phi_s = -0.087 +- 0.036 (stat.) +- 0.019 (syst.) rad \Delta\Gamma_s = 0.0641 +- 0.0043 (stat.) +- 0.0024 (syst.) ps^{-1} \Gamma_s = 0.6697 +- 0.0014 (stat.) +- 0.0015 (syst.) ps*{-1} Results for physical parameters compared with results from LHCb and CMS experiments.