Measurement of the Xi(-)(b) and Omega(-)(b) baryon lifetimes

Abstract

Using a data sample of pp collisions corresponding to an integrated luminosity of 3 fb−1 , the Ξ − b and Ω − b baryons are reconstructed in the Ξ − b → J/ψ Ξ− and Ω − b → J/ψ Ω− decay modes and their lifetimes measured to be τ (Ξ − b ) = 1.55 +0.10 −0.09 (stat) ± 0.03 (syst) ps, τ (Ω − b ) = 1.54 +0.26 −0.21 (stat) ± 0.05 (syst) ps. These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions.