Search for the doubly charmed baryon $it{Omega}_{cc}^{+}$

A search for the doubly charmed baryon $it{Omega}_{cc}^{+}$ with the decay mode $it{Omega}_{cc}^{+}toit{Xi}_c^{+}K^{-}pi^{+}$ is performed using proton-proton collision data at a centre-of-mass energy of 13$mathrm{,Tekern -0.1em V}$ collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of $5.4,mathrm{fb}^{-1}$. No significant signal is observed within the invariant mass range of 3.6 to 4.0$mathrm{,Gekern -0.1em V}/c^2$. Upper limits are set on the ratio $R$ of the production cross-section times the total branching fraction of the $it{Omega}_{cc}^{+}toit{Xi}_c^{+}K^{-}pi^{+}$ decay with respect to the $it{Xi}_{cc}^{++}toit{Lambda}_c^{+}K^{-}pi^{+}pi^{+}$ decay. Upper limits at 95% credibility level for $R$ in the range $0.005$ to $0.11$ are obtained for different hypotheses on the $it{Omega}_{cc}^{+}$ mass and lifetime in the rapidity range from 2.0 to 4.5 and transverse momentum range from 4 to 15$mathrm{,Gekern -0.1em V}/c$.

A search for $it{Xi}^{++}_{cc} rightarrow D^{+} p K^{-} pi^{+}$ decays

A search for the $it{Xi}^{++}_{cc}$ baryon through the $it{Xi}^{++}_{cc} rightarrow D^{+} p K^{-} pi^{+}$ decay is performed with a data sample corresponding to an integrated luminosity of 1.7 $mathrm{fb}^{-1}$ recorded by the LHCb experiment in $pp$ collisions at a centre-of-mass energy of 13 TeV. No significant signal is observed in the mass range from the kinematic threshold of the decay to 3800 $mathrm{MeV}/c^{2}$. An upper limit is set on the ratio of branching fractions $mathcal{R} = frac{mathcal{B}(it{Xi}^{++}_{cc} rightarrow D^{+} p K^{-} pi^{+})}{mathcal{B}(it{Xi}^{++}_{cc} rightarrow Lambda^{+}_{c} K^{-} pi^{+}pi^{+})}$ with $mathcal{R} < 1.7 hspace{2pt} (2.1) times 10^{-2}$ at the 90% (95%) confidence level at the known mass of the $it{Xi}^{++}_{cc}$ state.

First observation of the doubly charmed baryon decay $Xi_{cc}^{++}rightarrow Xi_{c}^{+}pi^{+}$

The doubly charmed baryon decay $Xi_{cc}^{++} rightarrow Xi_{c}^{+} pi^{+}$ is observed for the first time, with a statistical significance of $5.9sigma$, confirming a recent observation of the baryon in the $Lambda_c^{+} K^{-} pi^{+} pi^{+}$ final state. The data sample used corresponds to an integrated luminosity of $1.7,mathrm{fb}^{-1}$, collected by the LHCb experiment in $pp$ collisions at a center-of-mass energy of $13mathrm{,Tekern -0.1em V}$. The $Xi_{cc}^{++}$ mass is measured to be begin{equation} onumber 3620.6pm 1.5~(text{stat})pm 0.4~(text{syst}) pm 0.3~(Xi_{c}^{+})~text{MeV}/it{c}^{2}, end{equation} and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be begin{equation} onumber frac{mathcal{B} (Xi_{cc}^{++} rightarrow Xi_{c}^{+} pi^{+}) times mathcal{B}(Xi_{c}^{+} rightarrow pK^{-}pi^{+})} {mathcal{B} (Xi_{cc}^{++} rightarrow Lambda_c^{+} K^{-} pi^{+} pi^{+}) times mathcal{B}(Lambda_c^{+} rightarrow pK^{-}pi^{+})} = 0.035pm 0.009~(text{stat}) pm 0.003~(text{syst}). end{equation}

Search for the doubly charmed baryon $Xi_{cc}^{+}$

A search for the doubly charmed baryon $Xi_{cc}^{+}$ is performed through its decay to the $Lambda_c^+ K^- pi^+$ final state, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13$mathrm{,Tekern -0.1em V}$. The data correspond to a total integrated luminosity of $9,mathrm{fb}^{-1}$. No significant signal is observed in the mass range from 3.4 to 3.8$mathrm{,Gekern -0.1em V}/c^2$. Upper limits are set at $95%$ credibility level on the ratio of the $Xi_{cc}^{+}$ production cross-section times the branching fraction to that of $Lambda_c^+$ and $Xi_{cc}^{++}$ baryons. The limits are determined as functions of the $Xi_{cc}^{+}$ mass for different lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15$mathrm{,Gekern -0.1em V}/c$.