$\Xi_{cc}$ decays and properties

The $\Xi$ particles are baryons contains 2 constituent charm quarks in their structure which are expected to decay to high multi-body final states. The LHCb detector is ideally designed for studies of them due to its excellent particle identification and vertex reconstruction. Its capabilities in this area of physics was firmly demonstrated when LHCb announced the discovery of the first ever doubly charmed baryon, $\Xi^{++}_{cc}$, in decays of $\Xi^{++}_{cc} \to \Lambda^+K^-\pi^+\pi^+$ in 2017. This doubly charmed baryon was observed as a highly significant structure in the $\Lambda^+_c K^-\pi^+\pi^+$ mass spectrum from proton-proton collision data recorded by the LHCb detector in Run2. A yield of 313 $\pm$ 33 $\Xi^{++}_{cc}$ candidates is measured and the local significances is in excess of 12 $\sigma$ in the 13 TeV data. The properties of the peak suggest it is inconsistent with being a strongly decaying state. From the 13 TeV data, the mass is measured to be $3621.40\pm 0.72(stat.) \pm 0.27(syst.) \pm 0.14( \Lambda^+_c) MeV/c^2$. More analyses in the doubly charmed baryon sector using LHCb data are now well advanced. This includes, but is not limited to, searches for the singly charged $\Xi^{+}_{cc}$ state as well as the lifetime measurement of the $\Xi^{++}_{cc}$ state.