Measurement of CP violation in B0s → ϕϕ decays

A measurement of the decay time-dependent C P -violating asymmetry in B 0 s → ϕ ϕ decays is presented, along with measurements of the T -odd triple-product asymmetries. In this decay channel, the C P -violating weak phase arises from the interference between B 0 s − ¯ B 0 s mixing and the loop-induced decay amplitude. Using a sample of proton-proton collision data corresponding to an integrated luminosity of 3.0 fb − 1 collected with the LHCb detector, a signal yield of approximately 4000 B 0 s → ϕ ϕ decays is obtained. The C P -violating phase is measured to be ϕ s = − 0.17 ± 0.15 ( stat ) ± 0.03 ( syst ) rad . The triple-product asymmetries are measured to be A U = − 0.003 ± 0.017 ( stat ) ± 0.006 ( syst ) and A V = − 0.017 ± 0.017 ( stat ) ± 0.006 ( syst ) . Results are consistent with the hypothesis of C P conservation