中国物理学会高能物理分会第十三届全国粒子物理学术会议（2021）

A measurement of the lifetimes of the $\Omega_c^0$ and $\Xi_c^0$ baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment. The $\Omega_c^0$ and $\Xi_c^0$ baryons are produced directly from proton interactions and reconstructed in the $p K^- K^- \pi^+$ final state. The $\Omega_c^0$ lifetime is measured to be $276.5\pm 13.4\pm 4.4\pm 0.7\fs$, and the $\Xi_c^0$ lifetime is measured to be $148.0\pm 2.3\pm 2.2\pm 0.2\fs$, 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 LHCb measurements based on semileptonic $b$-hadron decays but inconsistent with PDG value before 2018, and provide the single most precise measurement of the \Omega_c^0 lifetime.