Measurement of the [bar over B][0 over s] → D[− over s]D[+ over s] and [bar over B][0 over s] → D[superscript −]D[+ over s] Effective Lifetimes

Abstract

The first measurement of the effective lifetime of the [bar over B][0 over s] meson in the decay[bar over B][0 over s] → D[− over s]D[+ over s] is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb[superscript −1], collected by the LHCb experiment. The measured value of the [bar over B][0 over s] → D[− over s]D[+ over 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 [bar over B][0 over s] mass eigenstate of Γ[subscript L] = 0.725 ± 0.014 ± 0.009 ps[superscript −1]. The [bar over B][0 over s] lifetime is also measured using the flavor-specific [bar over B][0 over s] → D[superscript −]D[+ over s] decay to be 1.52 ± 0.15 ± 0.01 ps.