Measurement of the ${\mathrm{\Xi }}_b^{-}$ and ${\mathrm{\Omega }}_b^{-}$ baryon lifetimes

Using a data sample of pp collisions corresponding to an integrated luminosity of $3\mathrm{f}{\mathrm{b}}^{-1}$, the ${\mathrm{\Xi }}_b^{-}$ and ${\mathrm{\Omega }}_b^{-}$ baryons are reconstructed in the ${\mathrm{\Xi }}_b^{-}\to J\mathrm{/}\psi {\mathrm{\Xi }}^{-}$ and $\Omega_b^- \rightarrow J/\psi \Omega^-$decaymodesandtheirlifetimesmeasuredtobe$\tau (\Xi_b^-) = 1.55, ^{+0.10}{-0.09}~{\rm(stat)} \pm 0.03,{\rm(syst)}$ps,$\tau (\Omega_b^-) = 1.54, ^{+0.26}{-0.21}~{\rm(stat)} \pm 0.05,{\rm(syst)}$ ps. These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions.