Precision measurement of the Λ_c⁺, Ξ_c⁺, and Ξ_c⁰ baryon lifetimes

We report measurements of the lifetimes of the Λ_c⁺, Ξ_c⁺, and Ξ_c⁰ charm baryons using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb^-1, collected by the LHCb experiment. The charm baryons are reconstructed through the decays Λ_c⁺→pK^-π⁺, Ξ_c⁺→pK^-π⁺ and Ξ_c⁰→pK^-K^-π⁺, and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the D+ meson, and are determined to be
τ_Λc+=203.5±1.0±1.3±1.4 fs, τ_Ξc+=456.8±3.5±2.9±3.1 fs, τ_Ξc0=154.5±1.7±1.6±1.0 fs,
where the uncertainties are statistical, systematic, and due to the uncertainty in the D⁺ lifetime. The measurements are approximately 3-4 times more precise than the current world average values. The Λ_c⁺ and  Ξ_c⁺ lifetimes are in agreement with previous measurements; however, the Ξ_c⁰ baryon lifetime is approximately 3.3 standard deviations larger than the world average value.