Measurement of the B-s(o) -> Ds-Ds+ and B-s(o) -> Ds-Ds+ Effective Lifetimes

Abstract

The first measurement of the effective lifetime of the ¯ B 0 s meson in the decay ¯ B 0 s → D − s D + s is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb − 1 , collected by the LHCb experiment. The measured value of the ¯ B 0 s → D − s D + s effective lifetime is 1.379 ± 0.026 ± 0.017 ps , where the uncertainties are statistical and systematic, respectively. This lifetime translates into a measurement of the decay width of the light ¯ B 0 s mass eigenstate of Γ L = 0.725 ± 0.014 ± 0.009 ps − 1 . The ¯ B 0 s lifetime is also measured using the flavor-specific ¯ B 0 s → D − D + s decay to be 1.52 ± 0.15 ± 0.01 ps .