Resonances and CP violation in B s 0 and B ¯ s 0 → J / ψ K + K − $$ {\overline{B}}_s^0\to J/\psi {K}^{+}{K}^{-} $$ decays in the mass region above the ϕ (1020)

The decays of B 0 and $$ {\overline{B}}_s^0 $$ mesons into the J/ψK + K − final state are studied in the K + K − mass region above the ϕ(1020) meson in order to determine the resonant substructure and measure the CP-violating phase, ϕ s , the decay width, Γ s , and the width difference between light and heavy mass eigenstates, ΔΓ s . A decay-time dependent amplitude analysis is employed. The data sample corresponds to an integrated luminosity of 3 fb−1 produced in 7 and 8 TeV pp collisions at the LHC, collected by the LHCb experiment. The measurement determines ϕ s = 119 ± 107 ± 34 mrad. A combination with previous LHCb measurements using similar decays into the J/ψπ + π − and J/ψϕ(1020) final states gives ϕ s = 1 ± 37 mrad, consistent with the Standard Model prediction.