Measurement of the B ¯ s0 meson lifetime in Ds+ π- Decays

We present a measurement of the ratio of the B¯s0 meson lifetime, in the flavor-specific decay to Ds+π-, to that of the B¯0 meson. The pp collision data used correspond to an integrated luminosity of 1fb-1, collected with the LHCb detector, at a center-of-mass energy of 7 TeV. Combining our measured value of 1.010±0.010±0.008 for this ratio with the known B¯0 lifetime, we determine the flavor-specific B¯s0 lifetime to be τ(B¯s0)=1.535±0.015±0.014ps, where the uncertainties are statistical and systematic, respectively. This is the most precise measurement to date, and is consistent with previous measurements and theoretical predictions.