Measurement of the $ {\varOmega}_c^0 $ and $ {\Xi}_c^0 $ baryon lifetimes using hadronic b-baryon decays

The lifetimes of the ${\varOmega}_c^0$ and ${\Xi}_c^0$ 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 ${\varOmega}_b^{-}\to {\varOmega}_c^0\left(\to p{K}^{-}{K}^{-}{\pi}^{+}\right){\pi}^{-}$ and ${\Xi}_b^{-}\to {\Xi}_c^0\left(\to p{K}^{-}{K}^{-}{\pi}^{+}\right){\pi}^{-}$. The measurement uses topologically and kinematically similar B − → D 0(→ K − K + π − π +)π − decays for normalisation. The measured lifetimes are ${\displaystyle \begin{array}{c}{\tau}_{\varOmega_c^0}=276.3\pm 19.4\left(\textrm{stat}\right)\pm 1.8\left(\textrm{syst}\right)\pm 0.7\left({\tau}_{D^0}\right)\textrm{fs},\\ {}{\tau}_{\Xi_c^0}=149.2\pm 2.5\left(\textrm{stat}\right)\pm 0.9\left(\textrm{syst}\right)\pm 0.4\ \left({\tau}_{D^0}\right)\textrm{fs},\end{array}}$ τ Ω c 0 = 276.3 ± 19.4 stat ± 1.8 syst ± 0.7 τ D 0 fs , τ Ξ c 0 = 149.2 ± 2.5 stat ± 0.9 syst ± 0.4 τ D 0 fs , where the first uncertainty is statistical, the second systematic and the third due to the uncertainty of the D 0 lifetime. These results are consistent with previous measurements performed by the LHCb experiment.