Measurement of the Ωc0 and Ξc0 baryon lifetimes using hadronic b-baryon decays

Abstract

The lifetimes of the ${\mathrm{\Omega }}_c^0$ and ${\mathrm{\Xi }}_c^0$ baryons are measured using a pp collision dataset collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb⁻¹. The charm baryons are produced in the fully reconstructed decay chains ${\mathrm{\Omega }}_b^{-}\to {\mathrm{\Omega }}_c^0\left(\to p{K}^{-}{K}^{-}{\pi }^{+}\right){\pi }^{-}$ and ${\mathrm{\Xi }}_b^{-}\to {\mathrm{\Xi }}_c^0\left(\to p{K}^{-}{K}^{-}{\pi }^{+}\right){\pi }^{-}$. The measurement uses topologically and kinematically similar B⁻ → D⁰(→ K⁻K⁺π⁻π⁺)π⁻ decays for normalisation. The measured lifetimes are$$\begin{array}{c}{\tau }_{{\mathrm{\Omega }}_c^0}=276.3\pm 19.4\left(\text{stat}\right)\pm 1.8\left(\text{syst}\right)\pm 0.7\left({\tau }_{D^0}\right)\mathrm{fs},\\ {\tau }_{{\mathrm{\Xi }}_c^0}=149.2\pm 2.5\left(\text{stat}\right)\pm 0.9\left(\text{syst}\right)\pm 0.4\left({\tau }_{D^0}\right)\mathrm{fs},\end{array}$$

where the first uncertainty is statistical, the second systematic and the third due to the uncertainty of the D⁰ lifetime. These results are consistent with previous measurements performed by the LHCb experiment.