Measurement of the CP-violating phase ϕs and the B0s meson decay width difference with B0s→J/ψϕ decays in ATLAS
A measurement of the B s 0 decay parameters in the B s 0 → J/ψϕ channel using an integrated luminosity of 14.3 fb−1 collected by the ATLAS detector from 8 TeV pp collisions at the LHC is presented. The measured parameters include the CP -violating phase ϕ s , the decay width Γ sand the width difference between the mass eigenstates ΔΓ s . The values measured for the physical parameters are statistically combined with those from 4.9 fb−1 of 7 TeV data, leading to the following:
In the analysis the parameter ΔΓ s is constrained to be positive. Results for ϕ s and ΔΓ s are also presented as 68% and 95% likelihood contours in the ϕ s -ΔΓ s plane. Also measured in this decay channel are the transversity amplitudes and corresponding strong phases. All measurements are in agreement with the Standard Model predictions.