Ξc baryon lifetimes

We report measurements of the lifetimes of the Λþc , Ξþc and Ξc 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 Λþc → pK−πþ, Ξþc → pK−πþ and Ξc → pK−K−πþ, and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the Dþ meson, and are determined to be τΛþc 1⁄4 203.5 1.0 1.3 1.4 fs; τΞþc 1⁄4 456.8 3.5 2.9 3.1 fs; τΞ0c 1⁄4 154.5 1.7 1.6 1.0 fs; where the uncertainties are statistical, systematic, and due to the uncertainty in the Dþ lifetime. The measurements are approximately 3–4 times more precise than the current world average values. The Λþc and Ξþc lifetimes are in agreement with previous measurements; however, the Ξc baryon lifetime is approximately 3.3 standard deviations larger than the world average value.