Charm baryons at LHCb

Abstract

The LHCb experiment collected the world's largest sample of charmed hadrons during LHC Run 1 and Run 2. With this data set, LHCb is currently providing the world's most precise measurements of properties and production of known charmed baryons, as well as searching for many previously unobserved states. The latest results on the charmed baryons described in this document include the lifetime measurement of the $\it{\Omega}_c^0$ and $\it{\Xi}_c^0$ baryons that are produced directly from proton-proton collisions and reconstructed in the $pK^{-}K^{-}\pi^{+}$ final state. The $\it{\Omega}_c^0$ lifetime is measured to be $276.5 \pm 13.4 \text{ (stat)} \pm 4.4 \text{ (syst)} \pm 0.7 \text{ }(D^{0}) \text{ fs}$ and the $\it{\Xi}_c^0$ lifetime to be $148.0 \pm 2.3 \text{ (stat)} \pm 2.2 \text{ (syst)} \pm 0.2 \text{ }(D^{0}) \text{ fs}$. Both results are consistent with the previous LHCb measurement based on semileptonic decays of $b$-hadrons. The latest results on the charm baryons from the LHCb collaboration also include searches for the $\it{\Xi}_{cc}^{+}$ baryon in the $\it{\Xi}_{cc}^{+} \rightarrow \it{\Xi}_{c}^{+} \pi^{-} \pi^{+}$ decay, the first search for the $\it{\Omega}_{cc}^{+}$ baryon in the $\it{\Omega}_{cc}^{+} \rightarrow \it{\Xi}_{c}^{+} K^{-} \pi^{+}$ decay, and the searches for the $\it{\Xi}_{bc}^{0}$ and $\it{\Omega}_{bc}^{0}$ baryons in the $\it{\Lambda}_{c}^{+} \pi^{-}$ and $\it{\Xi}_{c}^{+} \pi^{-}$ final states. No significant signals are found for neither of these decays, therefore upper limits are set on the ratio of production cross-sections times the ratio of branching fractions with respect to their normalisation decay.